Your holster is pretty good for the first time!!
An old cook told me once "patience makes the best sauce" Take your time , let your leather case out properly no matter how long or how you soak it, spray it, dip it in one toe at time, whatever super secret expert advice, I use Bobs method too, sometimes sometimes not. Cut an extra scrap of the same leather to test on, jab it with your finger nail or stamp, something every once in a while until you see it creating the right impressions, they should be crisp and darker in color and most importantly they don't show signs of fading or popping back out.
One thing to look for If your leather is to wet or your knife to dull it will make the swivel knife stick and jerk along as your try and cut.so if you feel that jerkiness then you know one of two things are hampering you.
Al Stohlman will never lead you a stray you can get his books cheaply, some for free in the Tandy library!!!
And my last suggestions on learning this craft, you will be using and looking at designs created by people who have been tooling for most of their natural life so don't expect your work to look as good for quite awhile. Just have fun with it and realize you will create your own personal techniques as you go. Also make some stuff without tooling too so you can learn the basics of sewing , dying, finishing etc. most of my tooling is still on scraps i usually do two or three practice pieces before committing to the final piece.
Good luck to you my friend we all started just like you at one time and are very willing to help.