I've been trying to find tutorials to help me understand direction handles in relation to corner points. The screenshot below shows a corner point and direction handle but it is only on one side? I was following a tutorial of tracing this image and in the video I could see two direction handles on this corner point but for some reason mine only has only has one direction handle.
Do it like this instead.
When you get to a corner anchor, click and drag out the curve handle, do not release the mouse click
Then, hold down Alt / Option
Drag to position the second handle in the direction you want to continue, release both the mouse click and Alt / Option key, and carry on
With the Direct Selection tool A click on the corner anchor point. You should see both handles
If you want to practice your skills, The Bézier Game is fun! I have no affiliation with the site.