Go ahead and plant them now. Some experts tell you that they have to be planted in the fall but not necessary. You could put them all in gallon+ sized pots and wait until fall but you could also loose them. They will send up some foliage but no blooms. Leave the foliage on until after frost as the nutrients in the leaves will gradually move down to the roots. Plant them about 4 feet apart from each other to allow the air to circulate around the plants. Will reduce the chances of diseases caused by molds and mildews. Peonies may take a couple of years before you ever see a blooming sized bud. While you are waiting for them to grow you can plant annuals or other short lived plants like pansies to fill in the space. Some bulbs can also be added as the spring blooming ones emerge before the peonies. Do not dig up in the fall as when the weather cools white roots will emerge. They feed the roots. If you have not already done do a search on them. YouTube has several videos on planting. Some good some only good for certain regions of the country. They bloom in the spring or early summer.