I personally started with straight wall pistol cases. Other than cleaning old brass there is not any prep work. Get a few hundred rounds under your belt, then step up to rifle cases if you want. The first time you go through and prep a couple hundred pieces of .223 will seem like it takes forever. Lubing, sizing, trimming, chamfering etc.. I now keep a few hundred prepped and ready to load whenever I feel the need.
Be ready though ,it’s an addictive hobby.
David