+1 for Godot. It seems like a great fit for your project. IDK about newbie friendliness, but if you already know python...
- Its scripting language is very similar to python. IIRC someone has a fork with python support.
- The download is super small
- Zero cost
- Open source / no telemetry
- Nice performance on low-end hardware
I spent some time with Unity3D prior to making the switch. No regrets at all. The big asset store was nice, but if you're not using it and have no love for Javascript/C#, then there isn't really much point IMO.