Short Recommendation:
For basics of the development cycle, read Accelerate by Nicole Forsgren and How Google Tests Software.
For AI image generation, install Stability Matrix and try popular Illustrious models.
Tracing can be done in GIMP (free) or an entry-level Photoshop package.
For coding, start with VS Code + Continue extension using a small Qwen model. Learn core concepts first (variables, loops, functions, OOP) via CS50, freeCodeCamp, or Unity Learn, then move to Unity.