Plasma isn't very beginner friendly. Carbine has good reload, damage, and limited dispersion so it's harder to just splay bullets everywhere and hope you get a hit. Also has surprisingly good accuracy at range, I've had good success sniping with carbine in a pinch. I'm also a big fan of LSMG, but other players don't seem to have high opinions of it.
I personally had a hard time with LMSG since it's just revolver with worse damage. If you want a semi auto primary RailRifle is a better option, I understood my mistake with LMSG so I sold it and got RailRifle, and it was a great decision imo.
But it's expensive as frick, and if you're aiming for your very first guns, then Revolver definitely is the best option. After it TrapMines are not half bad, they are as good as they are annoying.
And after that? I think that BlastGun is the cheapest primary that is really worth it, even though I hate using it. It shoots so fast and with a good aim (which you might have, considering you're still playing the game) you can take down an enemy in seconds, while they have a real hard time aiming back because of the fast shooting and the force on the hitted body. (sorry for the poor language lol)
As said, Carbine is also a great auto maybe worth the wait with spending, and PlasmaGun which is considered the pro gun really does take a skill, but has amazing results too.
