[Let's Go] Newbie help

My gf bought us a Nintendo switch with let's go eevee and im looking for some help as I've played Pokemon blue and yellow played Pokemon go but have a few questions
(1) if I sync my Pokemon go account with my name on the switch can I sync with my gfs account to?
(2)How do I trade with people to evolve my kadabra and are there any more Pokemon I need to trade?

Thanks in advance

If memory serves me correctly, you can sync multiple Pokemon GO accounts to your Switch. Namely you can transfer from multiple Pokemon GO accounts to the same Switch. How it's done, I wouldn't know(I don't own a Switch). As for the second question, I believe you need Nintendo's online service to carry out trades with other people. As I've noted, I don't own a Switch but to carry out anything with other people likely will require signing up for their online service(something that, if memory serves, was once free). Forget the cost but its like $35 a year or something like that. I recommend you hop onto PC's Discord to talk to people in real time and perhaps you can get your answers there along with getting your Trade Evolutions(Alakazam, Golem, Machamp and Gengar) and Version Exclusives(look them up. Pikachu has Oddish line, Sandshrew line, Grimer line and Scyther for starters).