Best bet is to have the posts set above ground on an appropriate sized concrete footing with an imbeded Simpson Type Post Anchor. Generally 24" or 30" square and 30" deep (if I remember correctly). HOWEVER footing sizing depends on the size of the deck posts required, the height of the deck, ground type, etc. Post pictures and you may be able to get better advice.

Or call in a deck specialist as you may be over yor head.................

I know it's "over my head" that's why I am asking here. Should I talk to a deck specialist first? Then would I tell the concrete people what I need? Pictures of the area are coming, I took the old deck down. It had 6 inch vertical posts in very little concrete, I don't think that was right.

Absolutely, hire a deck specialist or even a good general contractor. Let him handlke the concrete and the logistics of the rebuild.

A GC could handle the whole project (deck and patio). If you want to do or contract those things yourself, seems to me you need a deck plan first, so its known where the footings would go. There may be local codes as to the footing requirements. If the deck goes in first, then the patio can go down without having to make adjustments for the deck. Planning both together may provide the most advantageous result, as the placement of footings, etc. could be optimized for use of the patio below.

If a "deck specialist" can't handle footings....RUN!.Have a licensed contractor come out and work up an estimate for you. They should be able to answer all your questions, give you a ballpark price, and will be up to date on local building codes.