Ways to get more experience if already working full time in San Diego, CA

I currently work as a phlebotomist but we see like 3 patients MAX per day.

I still do not feel 100% confident in my skills (some of you may have seen my previous post about the schooling I went through) and I’m looking for ways to improve. Had this old lady today whose vein I could clearly see and i somehow missed it. I’m tired of missing these sticks and then having my boss immediately take over because I’m terrified of hurting the patient. I know confidence will come with it but man i am so not confident rn.

With that said I was considering trying to get a second job at a place where I’d get more experience, does anyone have any ideas? It’d have to be part time since I already work full time and in the evening. I don’t have kids or anything so should be fairly easy to work that schedule out.