If you don't want other people to use it, you should put it away somewhere.
If it's just for personal use, you shouldn't leave it out where others can see it.
ーIf you don't want other people to use it, you should put it away somewhere.
「他の人に使われたくなかったら、どこかにしまっておいたほうがいいよ」
to put away で「しまう」
ーIf it's just for personal use, you shouldn't leave it out where others can see it.
「自分専用なら、他の人の見えるところに置いておかないほうがいいよ」
personal use で「自分専用・自分用」
to leave ... out で「…を置きっぱなしにする・置いておく」
ご参考まで！
カナダ 
