I'm not pilot yet, just an enthusiast having some fun in MSFS2020.
What do those colored lines mean in Garmin avionics?
The various lines you see are used to demark certain aspects of the airspace such as controlled airspace (of differing classes) including terminal manouvering areas, restricted areas, military no-fly zones etc.
You get a slightly clearer picture (if you're used to reading sectional aeronautical charts) by looking at the real thing rather than a display on a simulated GPS.