I definitively recommmend you Fingerpicking etude. Only playing for 10 weeks and this one seems reachable.
The piece sounds nice too even at slow speed. I play it at 40 bpm instead of 90. So u see, you are not the only one to struggle haha 😉
For difficult parts, all i can recommand is to isolate them and play them over and over again… Till they become easy. Also work it very (very) slow first 😉 just saying 😀
Happy strumming to you !