Learn Hardcore German: Am Waldrand machen wir abends ein Lagerfeuer. - At the edge of the forest we make a campfire in the evening.

in (im = in dem) means inside something.
The Waldrand is the edge of the forest, not something you are inside.
So the natural preposition is an (“at”), not in.

You can say an dem Waldrand, but in normal speech and writing, Germans nearly always use the contraction am.

What case is Waldrand in here, and how can I tell?

Waldrand is in the dative case.

Why?

The preposition an is a two-way preposition (Wechselpräposition).
With location / no movement, it takes the dative:
- Wir sitzen am Tisch. – We are sitting at the table. (no movement → dative)
- Am Waldrand machen wir … – We are at the edge of the forest. (no movement → dative)

So the full (uncontracted) phrase is:

an + dem Waldrand (dative) → am Waldrand

Why does the sentence start with Am Waldrand machen wir … and not Wir machen … am Waldrand? Is machen wir a special structure?

This is normal German main-clause word order: the finite verb must be in second position.

German allows one element in the “first position” (Vorfeld). Here, that element is Am Waldrand. Then the finite verb (machen) comes, then the subject (wir):

1st position: Am Waldrand
2nd position (finite verb): machen
Then: wir abends ein Lagerfeuer

If you start with the subject instead, you also get a correct sentence:

Wir machen abends am Waldrand ein Lagerfeuer.

Both are grammatically correct. Starting with Am Waldrand puts more emphasis on the place; starting with Wir focuses more on the subject (“we”).

Is the word order Am Waldrand machen wir abends ein Lagerfeuer fixed, or can I move abends and am Waldrand around?

You have several correct options. For example:

Wir machen abends am Waldrand ein Lagerfeuer.
Wir machen am Waldrand abends ein Lagerfeuer.
Abends machen wir am Waldrand ein Lagerfeuer.
Am Waldrand machen wir abends ein Lagerfeuer. (original)

All are grammatical. The differences are mainly:

Information structure / emphasis: Whatever comes first is more “in focus” or “given as a frame.”
- Abends machen wir … → The time is highlighted.
- Am Waldrand machen wir … → The place is highlighted.

Inside the middle of the sentence, many teachers recommend Time–Manner–Place (TMP) as a guideline:

Wir machen [abends] [am Waldrand] ein Lagerfeuer.
(Time → Place)

But this is a tendency, not a rigid rule. Native speakers move these adverbials around for rhythm and emphasis.

What does abends mean exactly, and how is it different from am Abend or jeden Abend?

abends is an adverb that means:

“in the evenings” / “in the evening (as a general habit)”

It usually implies regularity or typical time:

Ich lerne abends Deutsch. – I (usually) study German in the evenings.

Compare:

am Abend – on/at (a) particular evening
- Am Abend machen wir ein Lagerfeuer. – We’ll make a campfire in the evening (today/that day).
jeden Abend – every evening
- Wir machen jeden Abend ein Lagerfeuer. – We make a campfire every evening.

So:

abends = “(in general) in the evening(s)” (habitual, typical)
am Abend = “on (that) evening” (more specific)
jeden Abend = “every evening” (explicit frequency)

Why is abends placed after wir and before ein Lagerfeuer? Could it go somewhere else?

Yes, abends is flexible. In the original:

Am Waldrand machen wir abends ein Lagerfeuer.

The “core” clause without the fronted phrase would be:

Wir machen abends ein Lagerfeuer.

Typical mid-sentence order often follows Time – Manner – Place – Object as a tendency:

Wir machen [abends] [mit unseren Freunden] [am Waldrand] [ein Lagerfeuer].

But you can shift abends for emphasis:

Wir machen ein Lagerfeuer abends am Waldrand. – Still okay, but less neutral.
Wir machen am Waldrand abends ein Lagerfeuer. – Also fine.

The strongest rule to respect is: in a main clause, the finite verb stays in second position. The exact slot of abends inside the middle part is more flexible.

What is the gender and case of ein Lagerfeuer, and why is it ein and not einen or eine?

Lagerfeuer is neuter: das Lagerfeuer.

In the sentence, ein Lagerfeuer is the direct object, so it’s in the accusative case.

Accusative forms for the indefinite article:

masculine: einen
feminine: eine
neuter: ein

Since Lagerfeuer is neuter:

Wir machen ein Lagerfeuer. – We make a campfire.

So ein here is the neuter accusative form.

What does the compound word Lagerfeuer literally mean?

Lagerfeuer is a compound:

das Lager – camp (also “storage,” but here: camp)
das Feuer – fire

So das Lagerfeuer literally means:

“camp fire” → campfire

In everyday German it’s exactly the same as English campfire: a fire you build outdoors, usually for warmth, light, or cooking, often when camping.

Why is the present tense (machen) used, if the action is in the evening? Shouldn’t it be future?

German uses the present tense (Präsens) much more broadly than English:

General habit / repeated action
- Am Waldrand machen wir abends ein Lagerfeuer.
  → “At the edge of the forest, we (usually) make a campfire in the evenings.”
Planned future events
- Context can make it future-like:
  Morgen fahren wir in den Wald. Am Waldrand machen wir abends ein Lagerfeuer.
  → “Tomorrow we’re going to the forest. In the evening, we’ll make a campfire at the edge of the forest.”

German can use a future tense (werden machen), but very often the present with a time expression (abends, morgen, später) is enough and more natural.

Is ein Lagerfeuer machen the most natural way to say “to make a campfire,” or are there other common verbs?

ein Lagerfeuer machen is completely natural and common.

You’ll also often hear:

ein Lagerfeuer anzünden – to light a campfire
ein Lagerfeuer entfache(n) – to kindle/ignite a campfire (more literary/formal)
ein Lagerfeuer schüren – to stoke a campfire (keep it burning)

Nuance:

ein Lagerfeuer machen – covers the whole process: arranging wood, lighting it, etc.
ein Lagerfeuer anzünden – focuses specifically on the act of lighting it.

For everyday speech, ein Lagerfeuer machen is perfectly idiomatic.

What is the plural of Waldrand and Lagerfeuer?

der Waldrand (singular) → die Waldränder (plural)
- Am Waldrand machen wir … – At the edge of the forest…
- An den Waldrändern wachsen viele Blumen. – At the edges of the forests, many flowers grow.
das Lagerfeuer (singular) → die Lagerfeuer (plural – no change in the word itself)
- Wir machen ein Lagerfeuer. – We make a campfire.
- Wir machen mehrere Lagerfeuer. – We make several campfires.

What is the difference between am Waldrand and an den Waldrand?

This is the classic two-way preposition pattern (an + dative vs. accusative):

am Waldrand = an dem Waldrand → dative → location / no movement
- Wir sitzen am Waldrand. – We are sitting at the edge of the forest.
an den Waldrand → accusative → movement toward a place
- Wir gehen an den Waldrand. – We are going to the edge of the forest.

In your sentence:

Am Waldrand machen wir abends ein Lagerfeuer.
→ The campfire is located there. No movement → dative (am).

Could I also say am Rande des Waldes instead of am Waldrand? Is there a difference?

Yes, you could say:

Am Rande des Waldes machen wir abends ein Lagerfeuer.

This is grammatically correct and means essentially the same thing: “at the edge of the forest.”

Nuance:

am Waldrand – very common, compact compound noun, sounds neutral and natural.
am Rande des Waldes – a bit more formal or literary in feel, uses a genitive construction (des Waldes).

In everyday spoken German, am Waldrand is more typical and straightforward.