You can also use your iPad as a second display for your MacBook. It's not exactly going to give you a lot of extra screen space, but it can be useful as a screen extension, to work more closely on detailed tasks or if you want to use your iPad as a graphics tablet with the Apple Pencil. To do this, you can use the Sidecar feature with macOS Catalina or later and a compatible ‌iPad‌ running iOS 13 or later. The easiest way is again via AirPlay.
Click the ‌AirPlay‌ icon (the rectangle with a triangle in it) at the top of the Menu bar and if you have a compatible iPad it will show up on the list. You can mirror your display or move your pointer over the full-screen button of a window and choose to move that window to your iPad display.