Title. Basically, this is a Greenfield deployment and I have zero history or experience with any pre-existing indexer. I mainly want to download shows from HBO or Disney or Netflix. id be happy to pay for a private tracker but the problem is the same, which one(s)? Adding that they need to be open.
Black Friday and christmas coming up so some less prestigious trackers do an open signup. Sites like TL are well populated so maybe take a look there. Else visit some opensignup pages and join them. Work yourself up from there to application trackers that only let users in if they are deemed worthy (seed well, no H&Rs, etc.).
The last part is probably only needed if you want either more rare or higher quality content.
Edit: Forgot to add: Personally I go with "The more the merrier." Just nake sure to visit everyone of them to not get pruned.
Another option (since this is prowlarr and not jackett or the torrent community: Usenet. Since you are willing to pay, take a look there.
But am not aware enough to say how fast they mirror P2P for current content.
Some trackers require you to login every X days (say 60 or 90 days) or show any kind of activity (seeding) else you get kicked from the server.
Be sure to read the rules of the tracker. Do it or regret it.