Ok this is an instructable that may help you create or finish that deck or level pad you wanted. this was built in 1 1/2 days. First find an area for your deck, then get an idea on the height you would like it to be. You will need a shovel, wheel barrel, string line, level,( water level works best), skil saw, hammer, screw gun ( drill), hand grinder, saw's all, or jig saw, speed square, nails, screws, couple bags of concrete, six piers, (more for a bigger structure), couple 8' 4x4's ,2- 8' 4x6 and 2x6 or 2x4 exc,
start by laying out your piers. dig down a few inches to fresh untouched ground. not too deep. get the corners all layed out square them they can be different elevations. measure from the top of the pier to your finish height, then subtract the 2x4 width and the remander will be your 4x4 height. do that to all four corners. Take a straight board and set it on the 4x4 posts, make sure they are all level when they are level and square tack down your girder, let it hang past your corners about 1' 1/2 or so. Ok then take your center piers and tack them to center of girder hanging and a quick wood form below and around it then pour your concrete around and under pier till concrete is a few inches higher then the bottom of your pier, let them dry for the day.
lay out joist nail them down and block it all the way around . Block on top of girders in between the joist, and block the end of the joist's. Make sure you add any backing ( blocking ) in an area that you will need to fasten your board down. Along the rock, this will all be covered by decking. . happy to answer any questions.