Looks like my Lady in Red Hydrangea. Mine doesn't get the red leaves and it doesn't look like yours does either but it has the red stalks

Here is a link that might be useful: Lady in Red

Definitely a white lacecap hydrangea. 'Veitchii'? or 'Lanarth White', maybe?. The differences are often pretty minor. Regarding care, they're all pretty much the same though; the plant looks plenty happy all in all, which is a good sign- the lackluster blooms certainly could be a light issue. Here in GA, lacecaps prefer morning sun or dappled light all day, but they would probably want a bit more sun in Maryland.

You could try putting down some time release fertilizer (we use a long-lasting mix with a 15/9/13 ratio of Nitrogen/Phosphorous/Potassium in the spring). This might help with blooms too.

As for care, watch for droopy leaves if there are long periods without rain. Once established, like yours appears to be, hydrangeas are fairly solid; but they can be a bit thirstier than other shrubs. Watering shouldn't be over-done, but a finger in the soil will tell you whether there's any moisture around for the root system. Droopy leaves are not necessarily an indication of lack of water, but certainly an indicator that something is making your plant unhappy. They may droop some during particularly hot days regardless of moisture level, though- and for this, nothing can be done but wait for them to perk back up.

The other main issues are pruning and winter protection. If you want to prune your hydrangea, either for shape, or size, or to encourage further flowering, it should be done just after the blooms die off, with a sharp, clean blade. Cuts should be made just above a pair of leaves. Winter protection shouldn't be much of an issue for you in zone 7, unless you hear word there's a particularly late cold snap coming your way- in which case you might provide cover with a lightweight sheet or the like; but even then your biggest loss is likely to be coming blooms, not the plant itself.

I hope you make some great discoveries about your new house and green spaces- good luck and good gardening!