My advice regarding this subject is not going to be very long winded. Different types of gemstones require equipment that is designed to handle the process that you desire. Tumbling requires a tumbler and polishing agents. Cabbing needs cabbing grinders and polishing wheels. Slabs and spheres have their own equipment, and faceting a faceting machine. FIRST find a teacher that will guide you along the path of your interests. It could be making cabochons. Cabs are beautiful and I especially love the agates for this art form. You don’t need to sit all day to have a finished product. It’s fun and artistically rewarding. There are many manufacturers of cabochon equipment on the internet and a lot of them have a good product. Your instructor will teach you on some of this equipment. This will no doubt have an influence on your choices. You can buy new or used. These machines are tough and built for a long life.
Carving is more difficult and requires an exhaust system. You use a flexible shaft with carving bits and an exhaust system that sucks away your carving scraps and blows them into a filter. Inhaling this dust will give you silicosis over a long period of time. That is why you need the exhaust!
Faceting can be learned in a few weeks with a good instructor once you understand the basic principles. You will learn on a machine that your teacher likes. You will become comfortable with that machine and in all likelihood will be pleased with the results. Like any art form; the longer you practice the more sophisticated you get. My teacher bought a new Ultra Tec faceting machine in the early 90’s. I bought his recalibrated used machine that was made in the 70’s for $600. I’m still using it today. 24 years later. I dragged it down here to Ecuador in a suitcase. Customs was a little rough with it and broke the lamp shade. I glued it back together. I cut a small amethyst to check things out and it’s still fine. That’s what I mean about tough! A new Ultra Tec today is $5,000. Make up your mind slowly and you will find something that works for you.