Cute game! To answer you questions- Learning game development is a long process. There are a lot of aspects to it, like 3D modeling, painting, sound design, programming, systems design and more, and there are very few people that are good at all of them. If you experiment and keep making games, without putting pressure on yourself, you’ll slowly learn what parts of game development you love the most or are best at. I recommend Riot game’s series “So you wanna make games?” on YouTube (: Finding 3D or 2D assets is just a matter of googling, there are many websites like kenny.nl and opengameart.org, but I recommend attempting to make the art yourself, as a beginner. Even if you’re not planning to take it very seriously, knowing a little Blender or Photoshop is very valuable. Getting better at it will take some time, but I find that pixel art is easier to start with compared to 3D modeling or painting. As long as you keep making games, you’ll get better. Keep participating in game jams, asking for and learning from feedback (maybe give yourself a bit more time next chance haha). Good luck!