Define "moving out"

If you go and stay with a friend until can afford to get your own place, does that count as living separate from your spouse? Do you have to pay that person rent and do you have to move out all your things? What are the minimum requirements that start “day 1” of the year-long separation period?

Yes, living anywhere aside from the residence where your spouse lives is sufficient to be separated whether or not you are paying rent. The date of separation is the date the spouses begin living separate and apart with at least one of them having the desire to remain separated.