He also has a ton of instructional videos about designing your own parts, so check them out as well.
However, if you have specific requirements for future projects, you are going to be better served by learning CAD. I promise that once you learn how to design your own parts, the usefulness of your printer will skyrocket.
I started learning Fusion 360 in 2020 and it has absolutely been worth it. I will say that if you are moving from TinkerCad to proper parametric modeling, the learning curve will be extremely steep.