Yep, 9.3 yds.  That's one (short) truck load.  Pour it all at once, should be a little cheaper than sending out 2 trucks for one load.  Maybe leave one end of your form open and just order 10 yds?  No one ever complains about having extra concrete.

2' spacing is fine.  Tie it together with these https://www.menards.com/main/building-materials/concrete-cement-masonry/concrete-accessories/rebar-loop-ties-1000-pcs/p-1444439550476-c-5642.htm?tid=-4778554997239769415&ipos=2

Using one of these:  https://www.menards.com/main/building-materials/concrete-cement-masonry/concrete-accessories/tool-shop-loop-tie-twister-tool/p-1444439574076-c-5642.htm?tid=-4467492430370036627&ipos=5

Set "height stakes".  Pound stakes in the ground inside your pour area so the tops end up level with where you want the top of the concrete.  Space them closer together than the length of your screed board.  Once you pass over them, pound them down and bury them.

We grooved some using the float with bungees wrapped around it.  Worked good.  Pulls kinda hard but grooves are still there 9 years later.

As far as what mix to order, let the guy at the plant tell you that. We usually get what they call an "ag mix". I have no idea what is or isn't in it.