OK, lets make this simple. Have you ever had your cock sucked? What did your cocksucker do that was pleasing to you? What did you enjoy having them to do? What were their technics? Just do what you like to have done to yourself. Whatever feels good, plus try experimenting a little to see what he likes and go with it. Have fun.
Nothing compares to the real thing
Forget the bananas. Get a long FLEXIBLE realistic dildo no more than 45mm in diameter and start sucking it. You will learn fast how to shield your teeth with you tongue and lips. Do it on an empty stomach and always spit the saliva. If you are a natural cocksucker and I'm sure you are your gag reflex will be much weaker after a few hours of training and you will be ready to take your first real cock down your throat with confidence. When you do get a real cock to use your mouth just make it sloppy. Spit the saliva and swallow the cum.
The first one is always scary. The first guy I sucked knew I was hesitant so he put me on my knees and pulled it out right in front of me. My head was now against the wall and I had nowhere to go. He edged forward and the moment his cock grazed my lips I lost it. I sucked his cock hard and fast and swallowed my first load of cum
Go straight to the real thing. You'd be surprised just how many men there are out there that would die for a little cock sucker like you. When the chance arises be confident, drop to your knees, don't ask. Get that cock out then look up at it's owner, I know from experience he'll nod or mumble, 'yes'. Most love it when you search for it, no hands. Do what ever it takes to make him feel like a god and he'll want as much as you can give. I find a tug on his balls is usually appreciated and in some cases spread them nuts apart, a little pain and pleasure! All love being wanked with your mouth from tip to the testicles and don't forget to swallow. You can drink it straight down or a favourite open your cum filled mouth for his gaze then swallow. Make it seem an effort, he'll enjoy the thought that you're struggling but keen to please. But the most important tip is to be enthusiastic, wait for him to recover then blow him again. If he's a one shot wonder let him rest with his softening dick in your mouth. I hope this helps.