I'm so glad that Agnes isn't $100's of dollars. I do have to, on occasion, debate spending even $35 or $50 on her services, but I'm always so glad I did. I wait too long, trying to figure it out on my own.
You can start off by just "checking in" with your cat. How are they feeling, etc. I was nervous the first time, had questions all prepared etc. It just takes on a life or a direction of it's own, it will be fine.