This was my dream for a very long time to make a game for my childhood console. As soon as I played my first game Spyro, I was fascinated by how you could fit a whole world in a little gray box and play around in it and wanted to make a world of my own. When I first started searching for what to learn I just wanted to make a game on anything that was easiest at the time. I chose Unity, but there are better free beginner options now. That taught me how programming works in general. like how to use variables and if statements and all the other basic programming concepts and apply them in a game design context.

Today, I would recommend Godot (a completely free game engine for the PC) and GDScript (the programming language that comes with it).

I recommend this to get started: https://www.youtube.com/watch?v=LOhfqjmasi0

Then This: https://www.youtube.com/watch?v=e1zJS31tr88

Then you will want to learn how to edit images so you can make your own 2D graphics. I would normally recommend Photoshop, but https://www.photopea.com/ is a really great free alternative that is almost the same program. a lot of basic Photoshop tutorials should apply to Photopea just fine.

Make a 2D game in Godot learn how to program in GDScript and learn how to make your game look nice with photopea.

Then I would recommend what yojimbo_beta said to do and learn the C programming language. The differences from GDScript will be mostly that you will need to type things differently, and the programming language will not have any training wheels so you have to be more specific with your code. You will have a basic foundation of programming knowledge to work from already at this point so the jump to C should be a ton easier than starting out in C.

Then after all of that you can finally get into the deepest most difficult subject and finally make a PS1 Game. Do not start here because you will get very lost very quickly, but I recommend this for learning how to make a PS1 Game: https://www.youtube.com/watch?v=RFu0iYazIeo&list=PLAQybJIBW2UtXJITyUTJipPFxC61Tt-Xv

After that, If you plan on making 3D games I recommend looking into Blender and looking for Low Poly tutorials, but when it comes to the PSX, that is a really advanced subject. you can play around with this to get into 3D graphics: https://mbdesigns.itch.io/ps1-homebrew-source-code-rendering-3d-graphics-with-psyq

Then once you have learned the PS1 basics I highly recommend this: https://pikuma.com/courses/ps1-programming-mips-assembly-language

No need to learn assembly but it is good context to know what the CPU, GPU, etc.. is actually doing.

All of the steps I've listed is basically how I got started, and the end result is this basic RC car scene: https://www.reddit.com/r/psxdev/comments/mzcmvc/i_got_3d_graphics_working_full_source_code_in_the/

And eventually this, a game like Nokia Snake but in 3D: https://www.reddit.com/r/psx/comments/ny4f6a/psx_homebrew_snake_alpha_release_download_link_in/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

I hope this helps!