Go to Strategy Section ffs, are you all blind? Seriously, there is a reason that section exists.

[p3]wind main full bt,

[p2]iruka full bt (the most important skill is shield),

[p4]kurenai full bt

that's all free

have you just started game? Or you not met a single SO6P team before in the game?

Well the standard team that works great is Naruto-Shisui-Earth Main-Bee. Bee is kinda important there because of double attack for Naruto.

The other teams i can think right now are Naruto-Shisui- Earth-Iruka or Naruto-Kazekage Gaara-Earth-Bee. You can try wind or fire mains.

Im sure there are few other teams that could work but without knowing what ninja you already have cant really do much.

don't know if this helps but Wind Main p4, HBH Kushina p2, 7S Bee p3 and Naruto p1 I am a Free to Player too but I don't know if you have this ones also wind main should have shadow clones for standard, one of the first 2 mysteries as attacks, the sage passive or shadow clone summon, wind blade passive for extra standard attack and the Wind chakra boost passive and for summons Fukuromaru for chase and monkey king for mystery