Hydrangeas are really easy care plants. I've grown them in full sun with adequate watering but I think they are happiest in part sun conditions. Your plant might of been a very small plant and spending the energy growing roots the first year. These types flower on old wood so if your plant was small and didn't have any old wood it would not flower. Hydrangeas are not fussy about the soil conditions either. The ph of your soil can determine the colour of the flowers. Alkaline soil produces a pink tone and here in Vancouver British Columbia the soil is more acidic and our hydrangeas are very blue. Watering in a new plant is one of the best ways to establish it. Fertilize in spring with a general purpose 6-8-6 around the base. I prune these types of hydrangea in the late fall after it has finished blooming. (around November here in Vancouver) I have also pruned this type in early spring before the leaves come out (above a leaf node). Hard pruning the hydrangea by about a 1/3 seems to produce lots of flowers for me. If your plant is still less than 2' tall I would just let it grow a bit more before pruning. Check out the link that Houzz member bepsf wrote for pruning info. Michelle also has some stunning examples of well grown hydrangeas. Well done! I hope this helps.