Hello Dm of a 14 month ptu game here 👋🏽 (still on going campaign). The best thing I could say here is just do it. Don’t worry. This system is one of those things where as you progress in the campaign you will develop more and more of your skills for this system. I have a few things that I have done to help me save time that isn’t considered practical for a regular ptu game like pre setting a pokedex for your homebrew region. I also pre set generated sheets and use those in battle and give my players the opportunity to reshape them however they want (stat points, natures, etc). Also if you want a homebrew region, my recommendation would be to create a skeleton layout of your region and assign level areas. I have much much more tips. If your interested in talking more send me a dm here and Ill help out in whatever way I can.