Find Minecraft?

I felt like I searched the whole Nether but I just can't find it. Neither a fortress nor fire. The trick with the sunflower seeds didn't work either. No matter how far I walk, you won't find anything.

Does anyone have any tips?

Do you have "generate buildings" on in your world? If not, there's no fortress. Lohen only spawn in the Nether Fortress biome.

Try the / locate fortress command

Then you will find a fortress

New world then you have to have a new seed for a fortress

sometimes walking for 2 hours to find a fortress

Then you are particularly unlucky. Try setting your Render Distance to 32 chunks or so so that you can see particularly far.