Yo, I use Godot! I switched from Unity recently. I think it would make a great next step for you. There's a few main reasons:
1. You aren't super experienced with programming things using raw code yet, since you've mostly used visual programming tools, so jumping straight into a code editor might be too hard right now. Godot is a game engine, so there's many things already built in for you that makes making a game much easier. You could probably recreate Zombiecats in a day by following a basic top-down game tutorial, saving you a lot of time!
2. You mentioned that your computer isn't very powerful. A lot of game engines have a lot of cool features, but also need more computer power to run. For example, Unity is also a good engine for beginners and professionals alike to use, and is probably the most popular. But it is several gigabytes to download, including the code editor that you need to write codes in it, and is a little laggy on my laptop when editing the code, so if that concerns you, you should start with something very small and portable. Godot is very small and much faster for me personally, and I was able to use it with Github Desktop to save my work online and work on it with friends.
3. Roughly speaking, Godot is primarily developed to support 2D games, while Unity/Unreal is primarily developed to support 3D games. If you're not making 3D games then there are many features you don't need right now, and that can overwhelm you before you even start.
Some things to consider before you choose it:
1. There are good tutorials online for learning Godot and GDScript. You can look at the documentation for Godot and study example projects. However, it's still a little limited compared to Unity, which has a LOT of tutorial material online since it's been around far longer. In general, though, if you're just starting out, there should be a lot of material to cover the basics of Godot.
2. You could look into GameMaker if you're still not confident with pure programming and want to stick with visual programming a little longer. But you'll eventually leave it once you learn how to write scripts yourself.
Good luck. The best way to find out which engine works best for you is to try them all out, but if that's not possible for you right now, Godot is totally fine. If you have any questions, you can definitely ask me and I can help you!