I am using CareCredit to pay for my surgery at the end of April. I paid out of pocket for my consult ($100) and 10% of the total price of the surgery to schedule it ($845). I then applied for CareCredit for the remaining balance ($7505). I asked my dad to cosign for me because I wasn't sure how rates worked. I have a credit score in the 800s, but I figured I could get an even better rate with a cosigner. Turns out that's not how it works, but whatever! They mail you a card with no expiration date, so you could apply now and use it whenever.
I don't think it's difficult to get approved from what I've read. I'd pay for the consult out of pocket if you can swing it, then finance the rest. If you have a relative or close friend that would be willing to cosign for you, that'll basically ensure approval.
I've been using Credit Karma to track my credit related stuff. Super helpful, and free!