Help building a free standing deck

I want to thank everyone in advance for the help and hopefully I don't sound too ridiculous asking the questions I will be asking. I am looking at building a free stand 20'x16' deck. I want it to run 20' along my house and extend out 16'. My first issue is ground clearance. It's good and bad. I don't need a permit since it'll be so low and not connected to my house but I am stumped on where to put the footings and support beams. My plan is to have doubled up 2x10's around the whole deck. Then run a pair of doubled up 2x10's down the middle parallel to the house. My questions are can I use 2x8's for the joists since I will have the beam in the middle and the will only span 8'? Next where and how many footings. I obviously can't do them in the corners next to the house so where should I support the portion next to the house and the rest of the deck with the footings. I know I sound like I don't know a thing but if the deck was a bit higher we wouldn't have any issues but this is really throwing me for a loop. Any help is appreciated. Thank you.

Help building a free standing deck