All Things Christmas

I know that I can only connect end to end the number that is recommended on the package, but I don't know how many strands or items can go in each extension chord and in each outlet.
I have two GFCF outlets at the back of my house, one at the side, and one at the front. I want to decorate the roof line and the front yard. The roof line requires about 10 strands of lights that can only connect up to 3 each end to end. The yard will have rope lighting of 18 strands (ok to connect) and a few other ornaments - lighted presents, trees, ect.
How do I go about doing this? Do I run multiple extension cords to the roof, and if so, how many connected strands can I put in each extension cord? Same question for the yard.
This is our first year decorating outside, and I don't want to have fuses blowing left and right.
(assuming 15 amps - I will make sure that they are not overloaded)