Applying for a Physics Masters as an international student
You can pose these questions to the institution you are most interested in applying to.

I doubt you need a Masters in order to apply for a Masters.

In general, I recommend applying for a PhD.  If you decide to stop with a Masters, that's okay.  Check this with the particular institution, of course -- but in general, I think that applying for the PhD program would give you the best chance of financial support (research assistantship or teaching assistantship).