Check out How Not to Die and subsequent books in that series.
you might give "How Not to Diet" a try. It has an accompanying cookbook that I found accessible.
There is an earlier book by the same author, "How Not to Die" which will dispel you of the idea that you're not getting enough salt and electrolytes and will likely convince you that you are very likely low on micronutrients.
Both are evidence-based, focused on quality studies and provide copius citations. I was confused what qualifies as processed food, until reading those.
For the mechanics of cooking, nothing beats just goofing around in the kitchen. Hands-on, like most things, is the best way to learn. Alton Brown's Good Eats is a great, entertaining take on hacking up a kitchen. He discusses gadgets, food science, and practice skills.
Best of luck on your nutrition, diet, cooking journey.