On the dating front, you and I are in a similar boat OP. I've done plenty of OLD (Guardian, Match, OKCupid) from which I've had plenty of dates. Ten years ago most of the people on online dating seemed to be decent people looking for a partner. It seems to have developed over the years to being a bit of a cesspit of married men, men who will spike your drink, ghosters, guys who just want sex but their profiles say they can want a long-term relationship. I've had loads of dates and the last one led to a relationship that seemed fab but then he just disappeared one day. He'd given me a false name - God knows who he actually was.
I've done speed-dating.
I have a very busy social life.
I play in orchestras, have been in a cycling club, badminton club (all because these are things I do anyway; not as ways of meeting men) and I've not met anyone through these things.
I've been on dates set up by friends (one of which led to a short relationship but he was a 41 yr old guy living with his dad who, for example, relied on his dad to give him a lift home after our dates rather than walk the mile home from the station (while I got on my bike to cycle 3 miles home on a dark country road). I'm very independent and couldn't get my head around the man-childness.)
For me, unless someone is a recluse, going along to evening classes etc. is unlikely to be the answer and it will be such a shame if every new thing you embark on is eventually overshadowed by the vague disappointment of 'well this is yet another place I haven't met anyone'.
For the moment I'm content being single. It's a nice place to be but it's taken me years to get here! And I know at some point in the future I'll go back to wishing I could meet someone.