Lets start off with the home button, this will probably need to be replaced. You can look your phone up in the IFixIt search bar and see from there how to do this repair.
With the WIFI, this could be caused from 1 of 2 things;
1. This could be the wifi chip on your logic board failing OR
2. this could be an issue with your router. How would you go with fixing this,
go to your router > unplug it > wait 30 sec. > plug it back in and let it load. Now see if it changed anything.
If it is still a problem, then please feel free to comment on this post and Ill get back to you soon!