There are thousands of CPT codes, and even more procedures, since one CPT code could describe multiple different procedures, and some procedures involve combining multiple CPT codes. There is no formal approval process for new surgical procedures, and there is no comprehensive list. New procedures are invented all the time.
Your best bet is to pick a specific area, then find a surgeon to shadow. A lot of details of surgical techniques are not written down anywhere, and you learn by working with other surgeons. There are a few books that go through the basic procedural details. For example, Zollinger's "Atlas of surgical operations" is a good reference for abdominal surgery, and Kandarpa's "Handbook of interventional radiologic procedures" is a good reference for interventional radiology procedures. "Biodesign" by Zenios is a good introduction to inventing new medical devices.
Best of luck!
Assuming you are in the USA- they just passed a law where all hospitals will need to publicly publish the list of all the procedures they do and the cost. Until now this,as I understand this was guarded very tightly and the common person would never get it. This information is maintained in what is called a “chargemaster” (charge description master). So I am thinking you can possibly download a few chargemasters abd then process it via queries etc and get a longer list of procedures. Hopefully this set you in the right direction.
But just out of curiosity, could you tell more about what you’re up to slash what you’re thinking about?