Breakdown of Først drikker jeg kaffe, så spiser jeg brød.
jeg
I
spise
to eat
brødet
the bread
drikke
to drink
Questions & Answers about Først drikker jeg kaffe, så spiser jeg brød.
Why is the verb before the subject after Først?
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.