Why my phone stuck on charging and not charging

# the phone is old i know but my iphone 8 got stolen and this my only hope.

1. And it was working fine and charging fine , but suddenly it started to get stuck on the Galaxy start logo sometimes. and then work as normal.
2. Now its charging so slow and if i took the cable of the phone it still shows me that its charging ( it makes me laugh so hard, sorry)
3. i realy need help because i cant afford money to fix it :/