Home button and wifi problems after changing my screen

Most likely you have to remove and reball / replace the Wifi IC. Heating it (Reflow) will most likely not work as there is underfill on the IC and heating it will cause the solder joints to expand and create more issues by bridging them.

You should google a reputable repair shop that does this type of repair locally if you can find one or use a mail in service. You can find several here on Ifixit business pros that will offer a reputable repair and most have a no fix / no charge policy.

There are also other components surrounding the Wifi IC that could cause the greyed out Wifi (Bluetooth spins but no connect). Without Microsoldering experience or tools of the trade will most likely cause further damage.