Probably lots of similar stories, have a look around.
So your first priority will be to get it charging again. But that probably won’t happen until you’ve disassembled the phone, cleaned all the internal contacts, made sure the connectors are properly aligned or seated. Allow some time to dry after cleaning the contacts with isopropanol and before reassembling.
Also read this. It’s about a FP4 but valid for all models! Use the correct screwdriver and at least moderate pressure to unscrew. Lighter pressure when reassembling.