What do I do if I don’t have Tefillin and can’t borrow someone else’s or get them
You should do whatever you can to get tefiilin. If you can’t then I would suggest to do, (not that it is a substitute for wearing tefillin but at least it is something) that you at least say the 4 parshiot that are written inside the tefillin. Which are shema, vhoyo im hamoa, (which you can find in the siddur) and also Shemos 13 1-16, which are the other two parshiot. You can also find them in many siddurim right after putting on tefillin before shacharis.