Chlorine demand or not . . . don't take a chance. Add 6 gallons of PLAIN 6% bleach ASAP, and then every evening till your kit is here!

Alkalinity and calcium are NOT urgent issues. Given your pH, nothing bad's about to happen on that front. Run your filter 24/7 and ADD THAT BLEACH!

And, please fill out the chart:
Pool Chart Entry Form
Pool Chart Results
For now, keep the chlorine high, the pH between 7 & 8, run the filter 24/7 and don't worry about anything else till later.