One step at a time basically! I'll tell you what, littlies are much easier than teenagers!
With DD, who is now 14, we started very early on the cooking! DH is a fab cook, so that one was easy. She's been cooking meals for a long while.
Going out, is the main one, I suppose. We let her go to the park (100 yards from home) during the summer months of yr 6. She was going to have to walk to school on her own, so we wanted her to get used to being responsible and us to get used to her going!
Boyfriends. Don't even go there!! I'm sure she's had a couple of boyfriends, but tbh, I don't encourage it. She knows how I feel about her being too young to be bothered with boys.
Sleepovers - been doing it for ages, here and at her mates. Only once or twice though, has she stayed at a secondary school friends, that I don't know particularly well. Everyone else has been mates for years.
Periods, I let the school deal with in Yr5 and then answered questions, if necessary!
The thing is, do all these things slowly now and tbh, it just kinda evolves. Don't worry about any of them, unless they happen really. When DD was 10 and I was thinking similar things to you, I would have been mortified to think she could do anything on her own. Now, at 14, she's off and running. Don't think twice about her telling me she's going on the bus to town or walking round to her mates house, 15mins away.