You really have no reason to be nervous at all. Ball pythons are one of the most docile snakes, and would rather curl in a ball and hide their head in fear rather than strike at you. If you give them no reason to strike, they won’t strike. Why would they bite you randomly for no reason? You’re not small enough to be food for them, and you’re not hurting them, so yeah, no need to worry, lol. Honestly I was never nervous when holding my bp when I first got her. Actually, I was nervous, but it was because I was afraid I might drop or hurt her in some way. I didn’t want to harm or scare her, so I was very gentle. Now I know my snakes limits and can read her feelings and stuff, so I’m at ease with her at all times.
I have been bitten once. It was when she was 6 months old. I had just got done feeding her a nice juicy rat, and she was nosing around and wedging her head between her digital thermometer and her cage wall. I simply wanted to move her head and point her to her warm hide so she’d zoom in there and digest for a few days. I do it all the time, and it usually works fine. But this time I forgot to let her rest a bit after the meal, so she was still in feeding mode, and didn’t want to be bothered with at the time. When I touched her, she swung around real fast and gave me a quick "leave me alone" bite on the hand. I laughed a bit, thought "aww how cute. my little girl has some spunk tonight", then moved her towards her warm hide, with no problems. The bite didn’t hurt at all, despite leaving a few fang marks and some blood. Honestly, if I didn’t see her strike at me, I wouldn’t have known she bit me. I don’t even recall feeling anything at all. She was so fast, lol.