A deck which will be 10x 12 ft how many and how far apart are the carrying blocks set?

dirt will work just level it

is it going to be 10 feet long and 12 feet wide ?

or 12 feet wide and 10 feet long ?

12 feet wide every 4 feet

10 feet wide every 2 feet

Things are more complicated than this. Is it a free standing deck? How tall is it?

Depending on your location, there are likely codes you must follow. I suggest you contact your local office of permits and inspections to find out more about the process.

Typically when a deck carpenter sets his 4 x 4, 4x6, or 6 x 6 pressure treated posts (they are sized according to the weight they will be supporting) they just dig a deep hole (proportional to the height of the deck... usually 30% of the post is underground...) they dig the hole about 2 feet in diameter, tamp the ground, plumb the posts then pour post cement at least 2 feet deep filling the entire hole around the post. They would also want to drill some rebar (1 or 2 pieces) through the post to help it grapple the cement.

Okay so 10 x 12 feet of deck is decent sized. Could end up holding a lot of people on it.

Some homes have special engineered joists that you cannot support a deck from. Like newer townhomes from NV homes. They have to be free standing decks supported on all sides.

So anyways, try asking your question again, and give specifics about the location of this deck (height, reference to other structures) and it's purpose. Someone should be able to help you design it appropriately.

Otherwise I would recommend you get some advice from a free estimate from a decent contractor out of the phone book you never have to see again! LOL. Just tell him you're waiting for some big check which might be months away. Then if he calls you later tell him some story about how your daughter's boyfriend went and built you one while you were away for a weekend...

Aren't I such a great help?