I was a personal trainer during undergrad and medical school. I helped Ken start CrossFit SouthWest while I was in medical school and had some extra loan money to work with. It was all our own equipment.
After getting my medical practice off the ground, I'm now working with Noah Providence of
www.providenceinstitute.com in an effort to get a Tucson CrossFit affiliate off the ground.
My suggestion, if you don't have deep pockets:
1. Secure a (relatively) steady income outside of training first. Learn how to save some money.
2. Get a basic trainer certification (NSCA, ACSM, NASM) and then get a basic training job. I worked at the Student Rec Center at the UA for around 3.5 years--weight room staff, group fitness (boxing and sports conditioning classes), personal trainer, and eventually head personal trainer.
2. Get your CF certification sometime in this whole process, after you get a basic training certification (you need that for insurance purposes).
3. Start obtaining basic equipment piece-by-piece at your house/garage. Train people as you can in that setting.
4. Make your dreams happen after that.
Hope that helps.