Super basic question here, as I don't think the delta site is clear enough.

I am a Virgin Atlantic silver member, as well as BA Executive Club member too.

Am I right in saying, that the main cabin on Delta requires you paying for baggage and First does not? This is on a domestic flight.

Also, how do those baggage prices work with multi-city bookings? Is the cost per bag segment based or for the whole booking? I want to do LAS>LAX then a few days later do LAX>SFO then another few days later SJC>LAS but all as one booking. What would the checked baggage price end up at?

Thanks in advance.