I'm in my late 30s, and getting married sometime next year. I didn't really start dating anyone until my mid twenties, and didn't really start getting the hang of how to act around women until my early 30s, and I attribute most of that to going to a variety of meetups with different meetup groups on Meetup.com and just trying to talk to people a little at a time and showing up to enough things that eventually we knew each other well enough that I started getting invited to things outside of the meetup groups.
I mainly went to board/video game nights, on hikes, movie nights, group dinners, museums, beach outings, and various one-off activities like scavenger hunts and mini-golf.
Eventually I became more comfortable being around women and stopped being quite so awkward around them. I got a few dates through meetup, but ultimately I met my fiancee through OKCupid. However, I don't think I would have been comfortable around her without the two years of going to as many social events that I could handle in anything that looked remotely interesting to me.
One thing I had to get over, also, is there are a lot of women in their twenties that aren't really emotionally available, for various reasons. Focused on their career, trying to figure out who they are and what they want in life, have their own struggles they're dealing with, etc. I would spend a ton of time and energy on certain women that I really fancied but they weren't really in the dating pool, even if they said they were. More like they were looking at it, and toying with the idea, but weren't serious about it.
When I did date people like this, it always felt like a struggle to keep things going, like they weren't trying very hard to keep in touch or communicate their needs or I had to keep making larger and larger gestures just to watch things fall through my fingers. It wasn't until I happened upon some relationships that were actually pretty easy to keep going and the other person made a real effort that I realized that the former was actually not the norm, and not the best I could hope for.
So I would recommend not putting too much energy into people that don't make an effort back. Just because they agree to dates doesn't mean that they're going to reciprocate your efforts. If you don't see them try to meet you at least 40% of the way (i.e. don't ever offer to pay for anything, don't come up with date ideas, don't initiate conversations, etc) after a month or two, it's probably not worth pursuing further, at least in my opinion.