If you need information on where to start then leave me a comment. I no longer post online tutorials as I have been badly hacked by revealing information about my OS and software of choice which reveal information about the specs of your computing ecosystem.
If developing a WordPress theme seems daunting then try building a “child theme” which is still challenging but not quite as enormous as theme development.
Good Luck! You CAN learn to code. All it takes is practice, patience, and attention to detail.