How to build deck starting in yard, ending on concrete slab?
I think your goal should be to have the deck a couple of inches below the bottom of the siding. If you use 2x6 joists, you'll need 5.5" plus the width of the decking, so you'll have to dig out the grass enough to get that depth. 

There are two ways to deal with the concrete pad.


You could put a 2x4 on it's side and shim it up with pressure-treated shims to get the height that you need. I'd attach it with Tapcon concrete screws. 
You could tear out the concrete pad with an electric jackhammer.


When I did my deck, I tore out the pad. It was a fair bit of work, but the deck was a lot easier to build.