how to make yourself like someone and how to feel comfortable around someone?

Be patient, friendly, pleasant and polite. Try to show him that you are a kind and caring person, and interesting to talk to. Talk to him when you can about school, sports, music, movies, books, hobbies, special interests, friends, family, pets, events that are happening around you or in your town, anything that might be of interest to him. Ask him questions about himself. Help him if he needs help. Show interest in the activities and issues that interest him. Pay attention to him, listen to what he has to say. Smile. Make eye contact. See how things develop.

Take some very quiet slow deep breaths when you are around him, very slowly in through your nose and then very slowly out through your mouth. It will help you relax.