as a rough guide
under 14 only holding hands and stuff maybe first kisses
14+ 2nd base only (ie kiss, toungue feel up over clothes mainly butt or boobs
15+ maybe starting to get to 3rd base hands under cloths, oral sex etc but ideally waiting till 16.
late 15 -18 for getting into sexaul relationships with support from grown ups and learning to handle them.
18 Plus for more serious stuff like 3 somes, live in relationships, pole dancing jobs, porn star etc, but best wait till 19/20 for that.
25 plus for more marriage and kids stuff