I must show immunity to MMR and VZV before starting school. I was only informed of the requirements on 6/6 yet I was given until 7/31 to submit compliant lab reports.
I received my first dose of Varivax on 6/10 and my second dose on 7/11. Meanwhile, I received an MMR booster on 6/14. Titers drawn on 7/26 showed positive MMR titers and a low "equivocal" VZV. My school discourages us from asking questions and prefers that we consult our healthcare provider. I am financially limited, and so I actually got my physical exam at walmart, ordered my own labs online, and was able to receive a few immunizations from a free clinic, and paid for others at the drugstore. I'm thinking I should wait another 10-14 days and be tested again before I pay to see a healthcare provider for advice. Does this sound reasonable? Could my VZV titers increase?

No, this does not sound reasonable, you need to be treated by a professional medical person, not treating yourself though walmart

Treating yourself through WalMart and the internet is downright foolish and dangerous.

If you live in the US there are local health departments who can do this testing for free or sliding-scale fees.