@raindrops_and_roses open the list, hit the 3 lines for settings in the top right, then hit "edit list".
That will show you who's in the list.
You have to do that for each list individually.
For finding hashtags to use, I always go with the easiest option. For Knitting, simply add a hashtag. Gaming, GamingNews, Fedi, Fediverse, Mastodon, AskFedi, are ones I browse regularly and are easily seen which topics they discuss. Keep it stupid simple.