You don't really "use" the objects you make. It took me awhile to figure this out too. The settlers will request things at the Camp Fire (tasks), which you go make at your shops, and once you make an item it goes to your Store House. Then go back to your Camp Fire to give it to the settlers and fulfill the task. The settlers take it out of your store house and "use" it. Each time you fulfill a task, you get a reward. Look at the request at the Camp Fire and you'll see that you will get XP and coins or NuBucks as rewards. Which, in turn, are required to build more items for your community and level up.

Shrubs

You can get crops out of season by spinning the reward spinner at the Game Hut and winning them. You get to spin the wheel each time you check in to get your daily reward. You can also spin the wheel as often as once every hour if you're willing to watch an ad video each time. You can also get out of season crops from trading.

You can build additional campfires from the decorations menu.