Yes, you can always make changes to the set up inside your base camp.
To relocate the buildings, hold and drop the building to the destinated positions. When you pick up a building, green boxes will appear to indicate the area that the building would take up. The relocation will fail If the building overlaps with other existing objects.
You can also add/remove decors inside your camp.
Steps to add decors:
2/ Select the [Decor] tag.
3/ Choose the item and drop it into your base.
Steps to remove decors:
1/ Select a decor.
3/ Tap [Confirm].
*100% of the decor’s cost will be refunded when it is demolished.