Learn Hardcore Czech: Dnes večer nechci jít nikam, chci být doma. - This evening I don't want to go anywhere, I want to be at home.

Dnes večer nechci jít nikam… = Tonight I don’t want to go anywhere…
Dnes nechci jít nikam… = Today I don’t want to go anywhere… (could mean the whole day)
Večer nechci jít nikam… = This evening I don’t want to go anywhere… (context usually makes it clear which evening)

So it’s not redundant; dnes večer is just more precise: this evening today.

Could I say dneska večer instead of dnes večer? Is there a difference?

Yes, you can say dneska večer. The meaning is the same.

dnes = more neutral / standard
dneska = a bit more colloquial, informal, often used in everyday speech

Both:

Dnes večer nechci jít nikam…
Dneska večer nechci jít nikam…

are correct. In writing (especially formal), dnes is preferred.

Why is nikam used with nechci? Isn’t that a double negative? Why not někam?

Czech uses negative concord: when the verb is negative, the pronoun is also negative. This is normal and not considered a mistake.

nechci jít nikam = I don’t want to go anywhere
(literally: I don’t want to go nowhere)

Compare:

někam = to somewhere (positive)
nikam = to nowhere (negative, used with a negative verb)

So:

Chci jít někam. = I want to go somewhere.
Nechci jít nikam. = I don’t want to go anywhere.

Nechci jít někam is felt as wrong or at least very strange in standard Czech.

What is the difference between jít, jet, and chodit here? Why is it nechci jít nikam?

Czech distinguishes type of movement and aspect:

jít = to go (on foot), one specific movement, usually future-oriented here
jet = to go / travel (by vehicle)
chodit = to go (on foot, repeatedly / habitually)

In your sentence:

Dnes večer nechci jít nikam…
→ implies tonight, for this one time, I don’t want to go anywhere (on foot or in general). In casual speech, jít often covers “go out” in general.

Other possibilities:

Dnes večer nechci nikam jet.
→ I don’t want to go / drive / ride anywhere (by car, bus, etc.).
Nechci nikam chodit.
→ I don’t want to go anywhere (habitually / in general, over a period of time).

So jít matches a single, concrete “going out” tonight.

Can I change the word order in nechci jít nikam? For example nechci nikam jít or nikam nechci jít?

Yes, word order is flexible, but it changes emphasis:

Nechci jít nikam.
→ neutral; plain “I don’t want to go anywhere.”
Nechci nikam jít.
→ slightly more emphasis on nikam (“I don’t want to go anywhere”).
Nikam nechci jít.
→ strong emphasis on nikam (“Nowhere do I want to go” / “I don’t want to go anywhere at all”).

All are grammatically correct; the original is the most neutral.

Why is there no já? Could I say Já dnes večer nechci jít nikam?

Czech usually drops the subject pronoun if the verb ending already shows the person.

nechci = I don’t want (1st person singular)
So já is not needed.

You can say:

Já dnes večer nechci jít nikam…

but then you put extra emphasis on I:

“I don’t want to go anywhere tonight (maybe others do).”

Neutral version:

Dnes večer nechci jít nikam…

Why is it chci být doma and not something like chci zůstat doma?

Both are possible; they are just slightly different:

chci být doma = I want to be at home
- Focus on the desired state: being at home, not out.
chci zůstat doma = I want to stay at home
- Implies you are already home (or normally would go out) and prefer to remain there.

In context, both are natural:

Dnes večer nechci jít nikam, chci být doma. (very common)
Dnes večer nechci jít nikam, chci zůstat doma. (equally fine, slightly different nuance)

What is the difference between doma, domů, and dům?

They are related but not interchangeable:

doma = at home (location)
- Jsem doma. = I am at home.
- Chci být doma. = I want to be at home.
domů = (to) home (direction, movement towards home)
- Jdu domů. = I’m going home.
- Vrátím se domů. = I’ll come back home.
dům = house / building (concrete noun)
- Ten dům je velký. = That house is big.
- Bydlím v domě. = I live in a house.

Your sentence talks about being at home, so doma is the correct form.

Why is there a comma before chci být doma? Could I use a instead?

The sentence actually consists of two independent clauses:

Dnes večer nechci jít nikam
(já) chci být doma

They are simply placed next to each other, separated by a comma.

You can also add a (= and):

Dnes večer nechci jít nikam a chci být doma.

Both are correct.

With the comma alone, it feels like two short statements in a row.
With a, it sounds more like “I don’t want this, and instead I want that.”

Why is present tense (nechci, chci) used for something in the future (tonight)? Is that normal?

Yes, it’s normal and very common in Czech (and in English too: “Tonight I don’t want to go anywhere”).

Czech often uses present tense to talk about near future plans or intentions, especially with a time expression:

Zítra jdu do školy. = Tomorrow I’m going to school.
Večer budu doma. = In the evening I’ll be at home.

Your sentence:

Dnes večer nechci jít nikam, chci být doma.
→ clearly refers to tonight because of dnes večer, even though the verbs are in present tense.

A literal future like nebudu chtít jít nikam (“I will not want to go anywhere”) is grammatically possible but sounds unnatural in this context.

How could I say this more politely, like “I don’t really feel like going anywhere tonight, I’d rather stay home”?

A very natural, softer version is:

Dnes večer se mi nechce nikam jít, radši bych byl doma. (for a man)
Dnes večer se mi nechce nikam jít, radši bych byla doma. (for a woman)

Key points:

nechce se mi = I don’t feel like (doing something)
radši bych byl / byla doma = I would rather be at home

This sounds less direct and more polite than nechci.