Before you start, back up your important data.
Some users try to use MicroG (open-source reimplementation) but eventually need real Play Services for banking apps or safety checks. NikGapps Core is the smallest step into the official ecosystem. nikgapps core android 12l
No. Changing GApps packages requires a clean flash (wiping system and data data partitions) to avoid severe system crashes and bootloops. Does NikGapps Core support Google Assistant? Before you start, back up your important data