our faucets part that allows the faucet handle to grip the wall base are broken and worn, we cant’ turn water on at all now, i have no clue what those little parts are called, i can’t find brand name on fixture, and have been to 4 different stores including home depot, does anyone know where else i could look?

I have a single handle bathroom faucet fixture and it is dripping. From what I have read I need to replace the washer. The trouble is, I have no clue how to even remove the faucet. thanks.