how to make your own game engine
Step 1: Learn Linear Algebra.
Step 2: Learn Python (or any language you want)
Step 3: Develop a Math Engine.
Step 4: Learn Computer Graphics.
Step 5: Learn OpenGL and do a lot of projects.
Step 6: Learn Design Patterns.
Step 7: Develop a Rendering Engine.
Step 8: Review Newton's Laws of Motion.
Step 9: Learn Computational Geometry Algorithms
Step 10: Develop a Physics Engine
Step 11: Develop a game, Test & Repeat
advanced :
step 1: learn pbr
step 2: learn modern opengl
step 3: learn vulkan and directx for good graphics
step 4: make raytracer if have rtx card