I have to wait like 20 minutes to get a game in the lobby, the tournaments are empty and that means I can't play with anyone

The site has been open for barely a week, you can't fault the mods and devs for trying. Computers which you can play are coming soon, and already there are strong players joining the site, which is only a good sign. Lichess wasn't full in the first week, be patience and the site will naturally grow. The lidraughts discord is also a good place to find games if you can't find any.

where can I find an invite to the lidraughts discord?

discord.gg/MjYecr5 is the offical lidraughts discord.