I wanna make an adult renpy game of my own, but I don't know what type genre within renpy games are easiest for beginner devs.
From my perspective, the two things that seem to cause devs to abandon projects the most seem to be some combination of:
1. It's taking too long to develop
2. No interest or lost interest in the basic premise
Based on this, my advice for starting a project you will confidently want to see to completion has less to do with genre, and more to do with:
1. Starting with a premise that you find compelling
2. Creating a short story around that premise to base your game around
I'd go so far as to say that for a first project, something you could complete in a single update would be ideal. There's two interrelated reasons for that:
1. You'll learn a lot on your first project no matter how long it is and will want to build on that knowledge moving into future projects
2. Another common reason for first time devs to abandon is being frustrated by how much worse their early work on their project looks compared to their most recent work