Learn Hardcore Russian: Снизу у входа стоит охрана, а рядом курьер ждёт меня. - Down by the entrance there is security, and nearby the courier is waiting for me.

Внизу́ is the neutral choice for a fixed location.
Сни́зу often contrasts with сверху (“from above”) and can mean “from below.” In everyday speech Сни́зу у входа is fine. If you want the safest neutral option for location, say Внизу́ у входа.

Why is it у входа and which case is входа? Could I say на входе?

У + Genitive means “by/at (near).” Входа is genitive singular.
На входе + Prepositional means “at the entrance (checkpoint/threshold).” У входа suggests being next to the entrance (often outside); На входе suggests the entry area itself (where checks happen). Both can work depending on nuance.

Why стоит охрана (singular), not стоят охрана?

Охрана is a collective noun (“security staff”) and takes a singular verb: стоит охрана. If you want to stress individual guards, use the plural noun: У входа стоят охра́нники.

What if there’s only one guard—how would you say it?

У входа стоит охра́нник. For two or more: У входа стоят охра́нники.

Does стоит here mean “costs”? How do I avoid that confusion?

Two different verbs:

Стоять (to stand): он стои́т (he is standing).
Сто́ить (to cost/be worth): это сто́ит (it costs). Here it’s стои́т (from стоять). Context and stress distinguish them.

Why use а instead of и between the clauses?

А lightly contrasts or juxtaposes facts (“whereas/while”), which fits well: security is at the entrance, whereas nearby the courier is waiting. И would just add the facts with no contrast. Both are grammatical; а sounds more natural here.

Does рядом need to be followed by с + noun? What is it referring to?

Ря́дом can be:

an adverb meaning “nearby” with no complement (as here): а ря́дом… = “and nearby…”
followed by с + Instrumental to specify: рядом со входом (“next to the entrance”), рядом с охраной (“next to the security”). Here it refers back to the just-mentioned place (у входа).

Are there other ways to say “near” here—у, возле, около, рядом с? Any nuance?

У + Genitive: “by, right at” (very common, slightly tighter proximity).
Возле + Genitive: “near, by” (neutral).
Около + Genitive: “near, around” (can feel a bit more distant).
Рядом с + Instrumental: “right next to.” All work with small nuance differences.

Can I change the word order in the second clause? For example: Меня ждёт курьер or Курьер меня ждёт?

Yes—word order changes focus:

Курье́р ждёт меня. neutral.
Курье́р меня ждёт. emphasizes that it’s me he is waiting for (not someone else).
Меня́ ждёт курье́р. emphasizes who is waiting for me (a courier, not a taxi/friend).

Which case does ждать take—genitive or accusative?

Traditionally genitive (кого/чего): ждать автобуса. Modern usage also allows accusative (кого/что): ждать автобус. Nuance (often subtle): genitive can feel more process/indefinite; accusative can feel more definite/scheduled. With pronouns like меня, the form is the same either way.

Do I have to write the letter ё in ждёт?

In ordinary print, ё is often written as е: ждет. It’s still pronounced ждёт [zhdyot], and ё is always stressed. For learning, it’s helpful to write ё.

Is “Снизу у входа” redundant? Aren’t there two location words?

They describe different dimensions:

Снизу/Внизу = downstairs/below (vertical).
У входа = by the entrance (horizontal/positional). Together: “Downstairs, by the entrance.”

Is the comma before а required? Do I need a comma after Снизу?

The comma before а is required (two independent clauses).
No comma is needed after Снизу here; Снизу у входа acts as one place phrase. You could write Внизу, у входа, стоит охрана… to add slight emphasis, but it’s optional.

How do you pronounce у входа?

Вход has devoicing: в becomes [f] before the voiceless х. So У входа sounds like “u fhó-da” (stress on хо: вхо́да).

Could I use дежурит instead of стоит for the guards?

Yes: У входа дежу́рит охра́на = “Security is on duty at the entrance.” Стоит focuses on their physical standing/presence; дежурит emphasizes being on duty/posted.

Is курьер the best word? What about доставщик?

For the person waiting to hand you a package/food, курье́р is standard. Доставщи́к is more “supplier/delivery provider” (often a company or role) and is less common for the individual in this context.

Can I say ожидает instead of ждёт?

Yes: курье́р ожида́ет меня is correct but more formal/bookish. Ждёт is the everyday neutral choice.