I’m new to the Forum myself, but have been leather working for almost 30 years. My best advice to get started in leather working would be to seek out a local supply house like a Tandy Leather or a saddle maker. They can show you basic tools and how to use them. If you have a Tandy Leather store near you, they will most likely have classes, will sell everything you need either in kit form or piece at a time. They may also have a referral list of local leather craftsmen who can show you and advise how to master basic to advanced techniques.
Leatherwork runs a gamut from very basic to advanced to the point of art form. Think of it like learning to draw. You can express a face from a simple smiley face to the Mona Lisa.
I have taught my children and Scout Troops basics and I have created some decent pieces one could regard as the work of Elves from Lord of the Rings. Everyone is a beginner at one time.
I would suggest ordering a catalog from Tandy. Besides offering tools, they provide patterns and instructionals within their pages. You can also purchase patterns, kits and tools for all levels of expertise from Novice to Master. Start with a simple project, like a simple pancake knife sheath. Unless you want to do design work and tooling right off the batt, focus on tools that punch holes for hand stitching, installing snaps and rivets, cutting, thinning and gluing.
Use sources like YouTube, Pinterest, and different online forums. It can be an inexpensive way to create basic goods like sheaths, bags, pouches, belts, etc. It can also become a profit generating hobby. What you put into it will determine what you get out of it.
Before you start your project, decide what you want the project to do. I like Pinterest for ideas. For example I have a knife I want a sheath for. It mine came with one, what do I like about it, what would I change? What other features would I like? Do I want it to just hang on my belt on my side? Right or left handed? Do I also want it to look western style, tactical, both? Write down your favorite features, take that list with you when you go to Tandy. Pics on your phone are even better.
Last advice, don’t waste leather or fixtures just practicing, practice with a goal like a finished sheath. You can always remake it if it doesn’t suit your needs, but you will learn from each project to do better the next.
Most importantly, don’t get discouraged. Rome wasn’t built in a single day!