Download mwsmith2's "bleachcalc" for your CYA (and many other) computations. Put it into the skimmer and run your filter 24/7...it'll take a few days to dissolve.

Shock is a process, not a product. Tell us what's listed on the "shock" label before you drop it in...it may not be Cl. Buy some bleach and put it in the first evening your pool is full. Enough to bring it up to about 12ppm will be fine. It'll disappear quickly the next morning and your fine to swim.

I'd keep putting bleach in there each evening after that up to about 4ppm. You'll still lose it quickly until your CYA starts to take effect but it will sanitize your pool. Enjoy your holiday.

You'll still be able to use that "shock" later but tell us what's in it first.