The Official Raspberry Pi Touchscreen Display comes with a set display scale out of the box, which is a good balance between the amount of 'stuff' you can see on the display, and being able to read characters/code easily.
Some projects need the display to scale things up/down to display more/less on the screen. This can be achieved by entering the following command in a terminal window:
xrandr --output DSI-1 --scale 2x2
You can play with the last part of that command to test different scales, for example, try using --scale 1x1 or --scale 0.5x0.5 for example.