how do i get more peers

The peers are other users who are seeding the torrent. In some way that I don't fully understand, your torrent client negotiates with the tracker (at gaytor.rent) and hooks you up with other seeders. You won't necessarily be connected with every other seeder. I don't know if there's a way to get the tracker to connect you to more seeders...perhaps another user can chime in.

How to download just one file from many in a torrent? This depends on what torrent client (software) you're using. I use uTorrent; when I open a torrent file it gives me a list of all the files available in the torrent, and I can tick/untick a box next to each file. Other torrent clients are probably similar. I find that if I download only a part of large collection of files, I will seed that material very quickly, and it helps my ratio. One thing to remember, though, is that even if you complete the download of your selected files, the system will still consider you as a leecher on that torrent--and this can be a problem if you have a small limit on the number of torrents that you can have downloading at once. You can find your limit of downloaded torrents by going to https://www.gaytor.rent/rules.php#96.

How to know which file to download from a collection with non-descriptive file names? This is often a problem. A good torrent uploader will include a folder of thumbnail images from the videos in the torrent. This is very easy to do, but many uploaders don't do it. I share your frustration. Sometimes I'll download just a few files (usually the smaller ones) to see if the material is something I like.