Ok then once again: Have a look at "immonet", I found some offers there right away.
There you go ;)
However, you should know this portal and a few others inside and out as a land or property seeker. At least for your region and a bit beyond, but for example, as a land seeker, you should also know all house offers. The rule is always to know the market and also find alternatives. Otherwise, good alternative offers slip away from you.
If you know some potential house sellers with whom you can imagine building, then I would also have them search for me (free and without early signature!!!!)
After all, they are the ones who want to sell you something: namely a house. For this they have their agents, who look for building plots. Prerequisite: you are in their database.