Yes, I have made oat flour in the past. I put it in my Kitchen aid attachment (grain mill). Just use quick or rolled oats.
There is a really yummy oat flour pancake recipe on the back of Bob's Red Mill oat flour (where I got the idea to mill my own). I have made oat milk too- just put the flour and water in the blender.
Sometimes I just put dry uncooked quick oats in small quantities in smoothies and milkshakes as a thickener.
You can buy "hulless" oats that don't have a coat/husk. You plant the seeds and up comes oats that you just put in your oat roller. Labor intensive to grow your own oats, but with that variety, it works well. I have tried it. The rolled oats look just like the ones at the store.
Regular oats are just about impossible for the homesteader to de-hull is what I have read (but haven't tried it).