In addition to researching what to eat, you might take a look at a book like “Fat For Fuel” by Mercola. It is important to know the science and the changes your body will go through as you adapt to a fat based diet. Fat For Fuel
Dietary science has come a long way in the last 50 years and you've apparently just missed all of it.
Read some nutrition books, that's the best way learn unless you want to sign up for online lectures. I'm not being snide, reading some books is the best way to absorb this information.
If you're only going to read one book, it should probably be this one. https://www.amazon.com/Fat-Fuel-Revolutionary-Combat-Increase/dp/1401954243/ref=sr_1_1?dchild=1&keywords=Joseph+Mercola+fat+for+fuel&qid=1601481643&sr=8-1
Now here's the TL/DR
Stop making erroneous assumptions based on painfully outdated science. Knowledge is available, you just have to stop taking old flawed science as gospel. Science and knowledge will always evolve over time, stop ignoring it.