I just made it to Arlong Park last night, so I have the 3* characters that you get in story mode up to that point, which is Luffy, Zoro, Nami, Usopp, and Sanji. I have not evolved any of them yet, though Luffy, Zoro, and Nami are at their current max levels. Other than that, the only other character I have that isn't a generic character is Coby.
Okay, shanks is your new default PSY captain.
Rakuyo is a good PSY beatstick but shanks has the better captain skill.
golden pound usopp's great in general, turn delayer sub on any team.
Princess vivi = a healer captain that won't boost damage, regular vivi works the same but heals less (only point in using regular vivi is if princess vivi costs too much for a proper team)
X Drake's a viable INT captain but you've got nothing close to an int team yet so .. no need to worry about him atm.
With the units you have you could make a psy team with synergy:
captain: shanks.
subs:
rakuyo
[any] vivi (not good, replacable)
golden pound
nojiko (not good, replacable)
Not a great team by any stretch, but everyone would benefit from Shanks' 2.5x boost.
Alternatively you can also make a healing team with vivi leading, my vivi team got me all the way to smoker before my damage output simply wasn't high enough.