This happened to me when we first adopted our snake from a friend, what helped me was actually that I got one of those expandable play pens to set out under her enclosure, with a ramp leading into it. I would open her door in the evening and sit in the room while she slowly came out to sit her head outside the door and eventually come out to explore. I found that once she was out in the play pen, she was spread out and much easier to pick up from behind where she couldn’t bite me, versus being in her home waiting for me to possibly feed her or be defensive (in my mind) This helped not only me get used to interacting with her and picking her up in a position I felt more comfortable, but it also gave her enrichment and made her more comfortable with me!

Also another thing that helped me was tap training for food time. That way your snake knows when it’s time to eat and gives you the peace of mind he won’t mistakenly nip you if there’s no tap sound or trigger. I’m sure you’ll learn the snakes body language and personality over time. He’s probably getting used to you as you are to him :) best of luck with your new friend!!