You must be so excited!

There is no reason why you can't swim in pH 7.2 and FC between 1 - 3. Your skin might feel a little dry and your eyes might burn at the lower pH but it won't harm you in any way. The FC level is a sanitizing level but make sure you keep it there and don't let it drop. That means daily testing and additions of an appropriate amount of bleach. Once you're past the initial marcite setting time you'll be able to add stabilizer to help protect against chlorine loss from UV.

In case you haven't found it yet, the Pool Calculator is a terrific resource to help you determine the amounts of BBB chemicals needed for your pool. For instance, it tells you that 38 oz of 6% bleach will raise the FC from 0 to 1.5 in 12,300 gallons.

Do you have a FAS-DPD reagent based test kit? It's a "must have", really.

Although that water is probably a little chilly have fun swimming!