Hello,
taking time, going slowly, communicating with the other is the key. No guy can learn what you like or dislike without you telling him, as one woman can be completely different from the other.
Also if he never done it before, flavoured lube can be a good idea. Could make things easier, but it can be done without it.
Finally, if he never done it before, he may be bit clumsy the first time, it is completely normal. I was the first time when giving head too. it is normal. We all have to learn this if we want to do it. if he does something what feels umcomfortable, then tell him that this is something you dont enjoy, but also tell him if something feels really good. Or moan if you are feeling more comfortable with words.
Good luck and have fun