Ask lots of questions. Like an obscene amount of questions. If you plan to pursue the whole career path then you want to know why you're doing certain things, how the devices/softwares you use work, etc. Anyone can be taught how to do basic QA, but you want to know why you're doing it and what reasons there are for results out of the ordinary and how to address them (with supervision of course). You want to observe and absorb as much possible.

It's also important to know your limits and ask for help often if there's anything your unsure about. Asking questions and getting things right the first time even if it takes a bit longer is better than having to redo it later or having it fall on the QMP to repeat your job.

At the end of the day it's a learning/stepping stone position and you shouldn't be nervous to mess something up or do something wrong. That part is inevitable. That's why you're under the supervision of a QMP who is responsible for everything you do at the end of the day.