Given how HVM are a minority, chances are you will mostly stumble across LVM in any particular activity. Even if you come across HVM, they may be taken, not compatible, or not interested in you.

You really shouldn't join an activity if your sole purpose is to meet men. You'll probably convince yourself you'll get to do/learn other stuff if Mr. Right doesn't appear, but honestly, if this is not an activity you would join if you were taken, chances are you don't like it much. You're also less likely to meet men you are compatible with if you join activities you're not a fan of. There's not much point in joining surfing classes if you dislike sports and are not into athletic guys despite how many men are into surfing.

As for activities designed for meeting singles such as speed dating events and Meetup groups for singles, well, all I can say is the success rate is not high. The only thing common between most of the participants is that you're all single so chances are you are incompatible with them. Notice how I used the word "most" as it's not unheard of for taken men pretending single to join these activities as they want to cheat or see if they can find someone "better" than their current SOs. I've also heard of speed dating companies paying men to pretend to be rich and successful singles at their events so that they can get more women join. And yes, some men join these activities in the first place as they have some deal breaker preventing them from finding love. You can give these activities a try, but don't expect too much. Certainly avoid activities for meeting singles if they cost a lot of money - it's probably not worth it.