At this point in the season it's a little late for autos. You could plant regular photoperiod plants and have them finish just as soon because there is only a few more weeks of veg time before everything starts flowering.
Regardless of that, You will need about 1 bag of soil per hole. You can mix back in a few shovel fulls of your local soil if its any good. It will add minerals and local micro life to your mix, and help it be less of a harsh transition between the native soil and your mix for the roots.
If you had more time to let the soil rest after mixing I would recommend a few amendments like kelp and alfalfa, but you don't have time
for that. If you add anything like that to the soil without giving it a few weeks to break down it will just burn your plants. You can top dress and make teas with them though. The only thing I would add this year to your soil mix are lime for ph control and calcium, and some rock dust for minerals and to give a home to fungal life. Fungi loves rock dust and will greatly improve the health of your plants and soil.
For every hole you mix of your base soil Id add 1 cup lime and. 4-8 cups of rock dust.
