Any files or folders deleted on Teams will automatically be saved into the Teams Recycle bin to allow you to restore later if needed. 

Step 1 - Open Teams and Navigate to the Team you wish to recover files from

Step 2 - Go into any Channel and click on the Files tab at the top

Step 3 - Click on Open In Sharepoint

Step 4 - Click on the Recycle Bin in the left hand menu

Step 5 - Choose the file or folder you want to recover

Step 6 - Click on Restore