Have you actually explored what it would take to become a dance instructor or where you would work once you had the credentials? Until you do that you won't know if becoming an instructor is even a possibility.
I suggest that you take a class at your community college that explores various careers. One of the things that you will do is take tests that will help direct you towards careers that fit with your personality, experience, and abilities. I can't think of the name for the tests right now.
It sounds like the careers you've been considering require training. Where will you get the money for expenses? In another post you said you didn't want to work in food service or sales. Most of us without money worked in mundane jobs to earn the money to go to school. I have a degree in Home Economics and did teach school for awhile but I didn't start out teaching school. I worked for several years before I was able to start college and worked while going to college.
If you're receiving state assistance, you may be able to get assistance with training and child care while in training. Have you looked into that possibility? My daughter used state assistance as well as grants and loans to get training as a medical assistant. She worked in that field for awhile but now works in a different field.
I suggest that you talk with your State Assistance office and find out what help is available thru them. Also check into the community college program. Then choose something in which to get started. You can always change your mind later. Many fields have similar requirements for beginning courses. Don't decide on a career. Get started! Stop stalling.
Yes, you will need determination and it will be hard work. Expect to struggle. As long as you want to succeed you will. If you continue to search for something that you know you will like you'll never choose anything. It sounds like you haven't found out anything about any of your choices. And you haven't considered starting at the beginning and working to the end to achieve something, anything.
If you want to be a dance instructor, research what it will take for you to be one. Go to dance studios and talk with dance instructors. Find out what it takes to become a dance instructor. Perhaps take the much shorter course to become an aerobics or jazzercise or pilates instructor and work for awhile so that you'll have experience and money.
You may be able to find a job in a dance studio so that you can see first hand what being a dance instructor entails. Stop just thinking about it and do something! It's normal to be fearful and uncertain. I was scared when I first started working. My first job was working in a credit office. I didn't know a thing about credit. I learned on the job, filing, and taking credit applications at the front counter as well as explaining accounts to customers. A really young mother worked as a cashier in the space next to the credit counter. Most of the counter and file clerks, that was me, were just out of high school and very inexperienced. We were mentored by older women who'd worked in that office for years, starting out in the front as we were starting out. It could've been a career for me but I knew when I started that I was working there to save money for college.
I learned a lot about the world and myself while working in that office. Looking back, I'm very glad that I had that experience. It did prepare me for the rest of my life.
I recommend that you just get started! Accept that you're anxious, uncertain and take that first step anyway.