I will separate this into expensive, still has a cost, and "free"

Expensive:

Car meetups and car modding

Horse based activities (learning to ride etc is group based)

learning a craft (ie blacksmithing, knitting circles, ceramics)

Swordfighting of various styles (east/west/modern/renaissance/polish drunk people in armour)

Warhammer

Cost, but not as much:

local hackspace

local cycle club

Local running club

Local team sports (real football, basketball, baseball, tennis, 5-a-side)

local choir (secular)

Amateur dramatics (highly recommended, darling.)

Free, but with connotations

Scouting adult leader

Local environmental people (ie park maintenance )

Animal shelter

charity shop

local choir (religious)

local organised religion

local political party organisation