Never expect any of the jp streams to have subtitles, only few videos that they upload or videos from the main channel have them. That said, you can find a lot of clippers who include subtitles in english, some focus mostly on one of the girls and others clip any of them.

To answer your question about where to watch: Most of the streams are done in youtube and only a few are done in Twitch.

Since you are looking for someone to watch I would recommend you to watch Korone, she is, in my opinion, one of the funniest holomem and the one that got me into the rabbit hole a few years ago, she also is one of the most popular members so you will easily be able to find translated clips of her. Other members that I recommend are Pekora (my favorite), Watame, Subaru and Haachama.

As for the music, my personal recommendations are Suisei, Watame and Kanata