How-To: Edit World Adventure Base Camp:
1. If your sim is on base camp, turning cheats on 'testingcheatsenabled true' and shift+click on the ground to enter build/buy mode. Money spent will be taken out of your sim's funds, and you will not have access to family inventory.
2. Go into Edit Town while at home, then click the (world of choice) icon in the upper left of the screen. This will load up selected world in Edit Town mode. (Recommended to Save As at this point.)
The lot maybe locked. If it is, enter "testingcheatsenabled true" and then "enablelotlocking true". Click on the base camp map tag to bring up the pop up window and click on the lock icon to unlock it. Go into build/buy mode and edit however you like.
Once you are done go back to Edit Town, (lock the lot again if it was locked before.) Go back to your homeworld's Edit Town (there should be a button at the top.)