I seriously suggest you get some experience in the field before you go starting off.
If you work as a service writer at 1-2 other shops for 1-2 years you'll be MUCH better prepared to go it alone.
You'll know where to get parts, fluids, etc. Plus you'll understand "Shop Supplies" "Disposal Fee" how to price parts, and many other things about the business that you only get to learn from experience.
I have worked in automotive for close to 10 years and I still managed to fail with my own shop. Don't do it, you need more experience first!!!