beautiful, nice color. Do you know which cultivar of quince it is? Looks a little like 'Minerva' or 'Texas Scarlet', but there are hundreds of named cultivars. A real bargain for the price.
You can prune back after flowering. Then after the spring bloom, I would pretty much let it grow until late summer. After the heat of summer has passed, is the time to repot Chaenomeles, flowering quince. This time of year they have a spurt of root growth, the trick is to repot just before or at the beginning of this spurt of root growth. The late summer repotting also avoids spreading of a nematode pest that Chaenomeles, flowering quince, are prone to get if repotted in late winter or spring.