Campsite: Definetly the Northern part of town with lots of Cedar trees and four-leaf clovers.
Town Hall: Bushes. Bamboos, in my opinion, is better for areas near the river in the southern part of town. I recommend either putting Holly starts by the Town Hall, or putting Azaleas/Olive bushes or both by the Town Hall. If you do the second one, put tulips because it looks amazing. I'm sorry, this is just what I did in my last town and it looked really nice. But do what ever you want, it's your town.
I'd say the little bit of land at the very top left of your map! Not much else you can put there, and you can make a little forest around it with a log bench and whatnot.