Hi Geekhack,
I am Swishy form the Keycap Designer Discord and Recently I and many members in my community have worked on making a guide to help people understand a little more about design and maybe help you with you first step in the design world.
The Guide is quite large in fact so large I can't post it all on one thread so instead here is a link to the Google Doc that host it The Guide (https://docs.google.com/document/d/1jjQghqjGP6BasZt4i0zTmK4p-gN_3IRhIAm2-CPE0kE/edit?usp=sharing).
I also have a discord where you can share and get feedback on your ideas and work on refining before you post your first IC. You can join that with this link Keycap Designer Discord (https://discord.gg/93WN2uF)
If you have any questions you can PM me or post here. I hope this helps!
Thank you for your time,
Swishy