My project is bitecritic.com, and its free. I try multiple stuff and in 2 months there are only 60 users.
Producthunt, tinystartups -> garbage, no value, no users
Reddit -> Mods block you on many topics, no signups from there
Tiktok -> AI generated video 1000 views.
Tiktok Ads -> 2k views per video 3 euros -> 5 signups
Instagram -> Most of the users are coming from here.
Friends and Family -> My real users :D