No one ever gives a perfect blowjob even the first time. Even I am still learning on different ways guys like it to be done. Everyone is different in the way they want pleasure.
The first time I gave a blowjob I was told that I needed more practice so I was a little embarrassed. I did not know what I was doing even though I had watched some porn it was still not what I needed to learn how to do properly. I kept trying to do what I had seen on the porno movies but some that had a little more experience in getting them just told me the same thing over and over again. But some did enjoy though.
Until one night this guy who was about 12 years younger than me, took me out into a field and wanted to have his way with me. He wanted me to get him hard with my mouth and he told me a few things I was doing wrong. Some guys don't want teeth on their cock but some do. My late husband was one that did. In fact my late husband told me for years when I finally perfected my own little blowjob technique that I could give porno stars lessons in how to give them.
I had a guy try to fuck my mouth one time for the first time and I thought I was going to choke to death. But it takes time and experience to learn how to do that. Plus you have to teach yourself how to relax your gag reflex even when I deep throat. I noticed some guys would get turned off cause I could not do it right but some were a little more understanding and just let me go at my own pace and actually taught me things like the guy 12 years younger than me.
The guy would tell me different ways he wanted me to suck on him and I tried to perfect each one. I even came up with some of my own later which to this day a guy who has gotten a blowjob from me will always come back for more and also when I describe my technique to a guy he will be so into it when reading that I got him hooked.