New to live sound

Currently on my summer break from university and I’ve been assigned to manage live sound at my church. I have no idea what I’m doing, I need help to better understand EQ and signal routing.

I’ve become more comfortable with the X32 compact from watching YouTube videos and online reading. Yet, it seems that feedback, noise, and quiet instruments are still present in both FOH and Stream mix.

Are there free online resources or volunteering opportunities in London which will help me become better at live sound?