Welcome to the fun Eberwolf
Feel free to ask anything. A first bit of advice is you will mostly likely will not build only one. So I'd recommend at least a 6 pack of plans to get a feel for a variety of types of bikes.
There will be the one you learn how to build
Then there will be the one you dreamed of building
And usually the one you truly love to ride.

I would look at the posts on the cycles you find most appealing. Then choose the ones you feel fit your desires.
Happy searching.