I have $16, 095 in June's Journey when I try to decorate the red check mark is on how do I unblock..

You have to make sure that the area you want to decorate is first clear of other decorations, including grass tiles. Once that area is clear, open your store, select the decoration you want, and drag it to that cleared space. The entire base should glow green (no red). Then you will see a green check mark to allow you to place it down.