@Artemis814pa Do you own the Spa Day pack? As far as I know (playing on Console) that's the only way to get a functional Spa with staff and customers. As for getting hair and makeup done, the Get Famous chair is used by the make up artist at the Movie Studio and is used just for you to change up your own Sim's look but not to hire staff at home. I always add one in a dressing room for a celebrity.
But with Spa Day I created a pretty cool space with staff turning up to do mani/pedis and massages and the pack was certainly improved by the recent pack refresh and nails for all of Simkind. Because it was just weird going to a spa with no fingernails...I mean... that was just embarrassing.
If you're on PC I don't know if there are mods to help.
