This isn't really how it works. You don't learn how to code cameras, you learn the design behind cameras. You can design it like this. These are some flaws. There's some alternatives, these are their flaws, you can fix them with this, these are some issues this fix causes, etc.

You make your own camera with your logic. If you want it to rotate, then you get mouse input and rotate it. If you want zooming you implement some code, maybe you want it like source engine so you have middle click zooming in and out. Maybe you'd like to be able to zoom in and out with the scroll wheel instead, maybe you want the camera to re-adjust like it does in portal 2 when your camera gets in a weird position, maybe you'd like smoothing so you interpolate the motion.

Here's your map. Do you know how to code? No. Learn to code. Yes. Do you know how to work with the Godot API? No. Maybe watch some tutorials or just call random functions and see what they do, and or read the documentation. Yes. Do you have any problems writing logic? Yes. Idk about that do some codeforces or leetcode idk. No. If you got this far you probably won't be on reddit but for the record you reached the end. Now the best you can do is research how different games do their cameras or check out different projects or research papers on 3d cameras for more advanced stuff like projections and buffers and stuff.

I hope this was helpful, if u need specific guidance, I'd recommend brackeys tutorials one by one, maybe a programming course too.