My first anal was also planned, with a casual friend and sometimes sex-buddy, with whom I'd only previously had oral.
Which enabled me to know he was smaller than average, and that I could trust him to use a condom, to go slow & easy, and to stop if I said stop. He did all those things.
So I had a wonderful "deflowering" with no pain or difficulty. In fact, doing it doggie-style at first, I was energetically thrusting back at him almost immediately, which really surprised him. He even began to doubt this really was my first time, but it honestly was. We did it 2 more times that night in different positions.
I give it a 5 out of 5.