What is it?
The first plant looks like bermudagrass. Small infestations of this can be dug out by hand, but you need to dig deep to remove all of the rhizomes (roots). Large infestations may need to be treated with an herbicide. You can find more information on the following page. https://extension.umd.edu/hgic/bermudagrass
Your hydrangea looks like it might be Hydrangea macrophylla. Within this species, there are "lacecap" and "mophead" types. We cannot determine what this is just by the foliage. Hydrangea macrophylla blooms on second-year stems (except for the "Endless Summer" variety, which blooms on the current year's stems), so the timing of pruning can affect flowering. Here is a guide to pruning hydrangeas. https://extension.umd.edu//sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/HG%20106_Prun...
Many Hydrangea macrophyllas where damaged this year due to late frost that damaged the buds. When this happens, there is nothing you can do but wait for next year. Your plant looks quite healthy overall. Keep it watered when we have periods of drought. Leave it unpruned this year and see if it turns out flowers for you next year.