How do I rotate an object in TinkerCAD?
1) Click on the object to bring up the rotation arrows, the picture below is pointing to them.
2) Depending on how you look at your objects the view of the rotation arrows will look different. (This allows you to rotate in different directions).
This is looking at the top vs. the side we were just looking at.
3) Left click and drag on an arrow to rotate.
4) Let go to stop rotating.
5) If you hold shift while rotating it will lock the rotations into 45 degree increments, which can be useful!