First time was… kinda disappointing

So before I decided to buy an aneros, I decided to read up on it first. I read all about getting in the right mood, flexing different muscles (PC and anus muscles, forgive my I forgot the technical term for the latter one)

In the end I decided to buy a Helix Syn Trident and got to town with it. Admittedly I was really stoked to try it out so I couldn’t really get into the mindset of “try to focus on what you’re feeling” and instead focused mainly on the “what am I supposed to be feeling” and “why don’t I feel that”. When I plopped it in it felt nice, and I could feel it brushing against my prostate. But after a while, say like 20 seconds, I didn’t feel anything, it just sat there in my bum.
I tried to flex the right muscles, but still only got the pressure against my prostate sensation for a few half seconds at the time with quite a bit of time in between them. Also I had the idea that I had to flex those muscles really hard.

Sooo I think I’m still doing something wrong (apart from the right mindset) and I have no idea what…
Any veterans with some advice for a beginner in prostate play?

P.S. Don’t get me wrong the orgasm at the end while jacking off felt amazing