iPhone 8Plus problems with charging port & super slow w super fast data, turn off WiFi and next day it’s searching for WiFi?

The cords used to charge them are fine w my sons iPhone but sometimes they work w my new iPhone 8Plus and then other times they don’t work, why? It doesn’t make any sense. I also have Verizon plan for data and it consistently is thinking always. They have not even placed a cap on it during busy times and still a problem. I have even replaced the phone once already and still a problem with that. Then I also don’t have home WiFi so I shut it off and yet it constantly is turn itself on and asking me to join random WiFi I. The area. It’s like it has a mind of its own and does what it wants? Help me please this is too expensive of a phone to have these problems constantly. I have only had it since Dec and two of them now to resolve the issue yet it hasn’t resolved itself