@Mr:
Sorry to keep asking questions but are there meta-teams? And what are good basic ones?
There are only a few teams where every member matters for general play, but you'll frequently see specific builds for Raid Bosses and sometimes other bosses. Most teams involve using the same character as captain and Friend Captain, though if you're just starting off that's a whole lot less likely. A couple examples of team builds:
A Gear 3 Luffy team is one of the most versatile out there because his captain's ability (3.5x attack boost after three consecutive Perfects) ignores both type and class. However, it requires good timing to hit the Perfects. You can sub the other members of the crew in or out as necessary to tailor the crew to your enemy. Typically you'll include GP Usopp, but other additions might be a damage reducer like Smoker, and orb manipulator like Doflamingo, an orb booster like Kaku, a healer like Brook or Marco, or someone like Mihawk who can cut the enemy's HP by a large percentage. G3 Luffy is a great Friend Captain if your own team doesn't have great synergy with your captain.
Another very common team is the Slasher team, led by Mihawk (2.5x Slasher attack boost) or Doflamingo (2x attack and HP boost). Both are fantastic characters with great stats and powerful specials, meaning you can double up on on for all-out attack or tankiness, or use both to stay more balanced. Slashers in particular are a very offensive class, with high attack and low recovery, making them good for blasting their way through a level but a bit less good for a sustained fight (but still good enough 95% of the time). The Slasher team I run is Mihawk (captain, HP cut), Arlong (high attack), Mr. 1 (attack/defense boost), Brook (healing, defensive debuff), and GP Usopp for turn delay. It's certainly not ideal, but I'm F2P and it's balanced enough to handle most things.
Another important style of team is the burst team, which focuses on orb manipulation and stacking buffs to deal the maximum amount of damage in one or two turns. Here's a classic PSY (yellow) burst team: Garp as captain and Friend Captain, Petty Officer Coby (sometimes referred to as God Coby), Impact Dial Usopp, Mr. 2 Bon Clay, and whoever you want in the last slot- let's say Franky. Here's how it works: when everyone's specials are charged, use one Garp. This turns all your orbs into yellow or meat. Then use Mr. 2 to turn the meat orbs to yellow, giving you all yellow orbs. Use Coby to double the effects of orbs and Impact Usopp to double the strength of PSY units. All together, you're doing 4 (captains) x 4 (boosted orbs) x 2 (Usopp) =32x base damage for one turn! If you're ideally fighting an INT boss, that's doubled again! The next turn, use your other Garp and manipulate the orbs with Franky to give your strongest members a 16x boost. You can usually only do this once per battle so make sure you make it count.
One last famous combo is the Laboon+Vivi combo. Vivi recovers health each turn and Laboon guarantees surviving a single blow with 1 HP if you're above half health before the hit. There are plenty of times when this combo won't work, but for some bosses it's possible to slowly whittle them down while effectively being invincible. Unfortunately, neither captain boosts attack and the rest of your crew needs to be low level enough for Vivi to recover half your total health, plus you can easily die if multiple enemis attack at once. Still, it's an option.