Apols if someone else has answered, but I'm posting from GB which tends to get its threading muddled.

Yes, the brown petal shrub is definitely hydrangea. Prune each branch back to a pair of fat buds - go lightly rather heavily so as not to destroy this years flowers. Get rid of it if you don't like hydrangeas. I'd probably get rid of it as they can get quite large and there are better ways of filling the space in a small garden, but for the moment it might be worth leaving as they produce a good display of flowers in the second half of summer followed, if you are lucky, by attractive colours on the dying bracts.

Next pic is a variegated Lamium - may have either pink or yellow flowers. leave it as useful ground cover, but be prepared to yank some of it out if you want to plant something else there instead. The lacy leaves are Herb Robert, a british native with pink flowers (there is a white flowered garden variety) - it's too aggressive a seeder, so I'd get rid.

Final pic has grape hyacinths, again a matter of personal preference. Nice flowers, but rather a lot of floppy leaves. And the other leaves in the pic (below the dead stems) look like the yellow poppy - keep them and see what comes up.