Learn Hardcore Norwegian: Først drikker jeg kaffe, så spiser jeg brød.

Because of the V2 rule in Norwegian main clauses: the finite verb must be the second element. When you front an adverb like Først, the verb comes next, then the subject: Først drikker jeg kaffe. Without fronting, the default is subject first: Jeg drikker kaffe først. The same happens after så: Så spiser jeg brød.

Do I need the comma before så?

Yes, it’s standard to put a comma between two independent main clauses: Først drikker jeg kaffe, så spiser jeg brød. You could also separate them with a period or a semicolon. If you add og before så, the comma goes before og: Først drikker jeg kaffe, og så spiser jeg brød.

Does så mean then or so here?

Here så means then (a next step in a sequence). Så can also mean so/therefore in cause–effect sentences (Jeg var trøtt, så jeg la meg), and it can be an intensifier (så stor = so big). Context decides the meaning.

Can I just say both actions in one clause: Først drikker jeg kaffe og spiser brød?

That sounds like you drink and eat at the same time. If you want a clear sequence, keep så (or a full stop): Først drikker jeg kaffe, så spiser jeg brød. Alternatively: Først drikker jeg kaffe. Så spiser jeg brød.

Where does negation ikke go in these clauses?

In main clauses, ikke comes after the subject and the finite verb. Examples:

Først drikker jeg ikke kaffe.
Så spiser jeg ikke brød. Don’t put ikke at the very end: Først drikker jeg kaffe ikke is wrong.

Why is there no article before kaffe or brød?

They are used as mass nouns here, so no article is needed: drikke kaffe, spise brød. If you mean one unit, use a measure word:

ordering a coffee: en kaffe or en kopp kaffe
a slice of bread: en skive brød or en brødskive If you mean a whole loaf, you can say et brød.

Is brød countable or uncountable?

Both, depending on meaning:

Mass/food in general: Jeg spiser brød.
A loaf (countable): et brød, plural brød, definite plural brødene. Saying Jeg spiser et brød means you eat a whole loaf.

How do I pronounce tricky parts like først, jeg, and brød?

ø (in først, brød) is like the vowel in British English bird, but with rounded lips.
jeg is commonly pronounced like English yay, often [jæi] or shorter [jæ], depending on dialect.
Many dialects make rs/rt/rd/rn/rl retroflex; først often sounds like føʂt (a kind of sh + t).
Double consonants (like kk in drikker) signal a short preceding vowel.

Can I use før instead of først?

No. først means first (as an adverb in a sequence). før means before and introduces a time relation:

Før jeg spiser, drikker jeg kaffe. (Before I eat, I drink coffee.)
Først drikker jeg kaffe, så spiser jeg brød. (First … then …)

Does the present tense here refer to the future too?

It can. Norwegian often uses the present for planned or scheduled future: I morgen: Først drikker jeg kaffe, så spiser jeg brød. To make the future explicit, you can use skal: Først skal jeg drikke kaffe, så skal jeg spise brød.

Is Først så drikker jeg kaffe acceptable?

It’s common in informal speech, but many teachers and style guides prefer not to double up. Use either Først drikker jeg kaffe or Så drikker jeg kaffe in writing.

Can I drop the second jeg like in English (… then eat bread)?

No. Norwegian normally repeats the subject in each clause: … så spiser jeg brød. Omitting jeg is considered telegraphic or nonstandard outside of notes and headlines.

What are some alternatives to så?

deretter (more formal): Først drikker jeg kaffe, deretter spiser jeg brød.
etterpå (afterwards): Først drikker jeg kaffe. Etterpå spiser jeg brød.
senere (later, less immediate): Først drikker jeg kaffe. Senere spiser jeg brød.

Can I move først to the end: Jeg drikker kaffe først?

Yes. That’s very natural when først is a time adverbial. Jeg drikker først kaffe also exists but puts extra emphasis on the order and can sound more marked. With først in front, remember V2: Først drikker jeg kaffe.