Besides Mervina, you can have 3 other followers at the moment.
You can recruit the mercenary orc at the mercenary camp.
You can do a quest to Stella and find another follower.
After the village upgrade, you can try to find another member exploring the Forest map. Defeat her and spare her, then talk some times with her, and she'll offer to join you.
You can't join the guild in this game version. Will come in future updates.
Good game.
With affection;
C.M.Cas Games