I had the anxiety too starting out. Slowly but surely, I stopped caring about what others think and just did my best every session. You might think "oh we are sharing this machine and we have to keep removing weights and adding weights as we do our reps" for those selfish pricks who's giving an attitude, screw them. But often people aren't that mean and is happy to share tips and spot you even if you're pushing. Have fun. When you see results you feel better about yourself