I feel your pain - there's just so many possibilities! I have constant ideas but not enough time to try all of them!
What I liked doing at the beginning was making a simple subtractive mono synth and then experimenting with it - what happens if I have a bunch of different filters in parallel with offset cutoffs?... ....hmm, sounds nice... ....what happens if I send different lfo's/envelopes to them, each running at different speeds?... Etc.
I initially made some different patches along the lines of what I wanted - a synth, a sequencer, a Looper, some fx. And once I had the basic patches in place I had a lot of fun using them as templates and then experimenting with them and combining them- swapping out objects, using maths objects to manipulate controls, etc.
So I'd say, make some simple stuff and then just play around, ideas will form and it's a good way of learning the patcher.
It can be hard to finish stuff with the constant 'What if I try...' voice in my head!