The issue is that as a student on a F-1 visa you are not allowed to work at all at an off campus job.
https://www.uscis.gov/working-united-states/students-and-exchange-visitors/students-and-employment
Depending on what your degree is in, you may be eligible to work for 1 year in a field related to your major as part of your OPT. (Optional Practical Training) You could potentially work during this year and accumulate hours toward fulfilling PA school requirements.
However, there is no guarantee your US college advisor will approve OPT for a job that doesn’t require a bachelor’s degree. (And phlebtotomy, CNA, MA, EMT, paramedic, etc do not require a college degree, just a vocational certificate. These are the typical jobs that PA students do in get their hands-on hours in. )