I have 64 druid and 33 warlock. Im probably gonna do raid mostly and sometimes pvp. I know druids are more welcomed to raid than warlock but I heard feral druid got nerfed in pvp after the new expansion. However, my druid is raised by my friend so i dont know how druids work and since it is hybrid toon, people say druids are complicated to learn. Will I be able to learn druid when I get to 85 and are warlocks welcomes in raids as dealer?

It all depends on what role you want to play. If you want to go for dps, its best to choose warlock and spec in destruction. If you want to tank, then it's best to go for Druid and spec in feral, while using bear form during raids and PvP. You could also spec a druid in a different talent tree to go for dps, but it's hard to beat warlocks in dps, so if you want to cause damage, go with warlock.