I live in Northern IL, and need advice on pruning hydrangeas. First thing I read online was that I needed to identify the type of hydrangea and whether it blooms on old growth or new growth... which is where I am stuck.. It's currently March, and my blooms are showing both buds on the old branches, AND i see some new green shoots at the base. Are they the same plant? What type of hydrangea do I have and any tips for pruning it for USDA zone 5-7?

Here is a picture of the hydrangea. Last year's flowers are looking nice and tan, BUT you also see some green shoots at the base:

Green shoots at the base:

Bud on existing branches: