So is the bamboo grass a house decoration then?
Yes, Bamboo grass is the item for your home, and the Bamboo shoot are the trees.
The way you trade a villager is that, when a villager have packed up (that?s the date they tell you that they?re gonna leave).
you invite the other person to your town, and then they talk to the villager, and if there?s enough space in the other persons village, the villager will move in there the next day.
it require a lot of luck and planning though, because you need to have a free spot the day the villager is moving from the other town, unless you TT that is, I don?t time travel, so I use the reset trick. link in my signature (shameless plug), if you do Time Travel there's a method called the 2 day TT (or something like that) where you TT 2 days into the future, talk to all your villagers, to see if anyone of them are gonna leave, if a villager you want to leave tells you that they?re gonna leave, then you just TT 2 days back again and they should be gone, if a villager you don?t want to leave tell them not to, and then TT 2 days back, ask the villagers again, then TT 2 days into the future, keep doing it until you get rid of the villagers you want. (at least that?s what I heard, I haven?t tried the 2 day TT thingy, since I?m not a TT, so you should probably ask someone about that first before you do it).
I hope that helps ^^