Most people on LCHF avoid grains because of the high carb content, so gluten free works perfectly with this WOE.
Read information about gluten here https://www.glutenfreesociety.org/guidelines-for-avoiding-gluten-unsafe-ingredients-for-gluten-sensitivity/
They pretty complete lists of foods to avoid.
Basically avoid grains and flavorings, drinks, and food additives that contain grains.

I bake only with coconut flour, flax meal, hemp and chia. I have a bit of buckwheat for some baking for my kids, but otherwise it is the "flours" I mentioned. The other GF flours are really high GI. Especially the starches. It is often easiest to skip them.

My son and I both have celiac disease but for myself, I do almond and coconut flour