If you are talking about scanning with the discovery scanning when you jump into a system and then looking at the system map and not seeing anything except the sun and asteroid belts then after you scan the system you have to go into the FSS and zoom in on each body and scan each individual body to get them to show up in the system map. Google "Elite Dangerous 3.3 FSS instructions" and read the threads that popup up and watch a couple of youtube videos, this will teach you what you need to get started. After that it is just spending enough time in the FSS scanning stuff to get use to how it works. It took me scanning at least every body in 20 systems to learn the in and outs of scanning bodies with the FSS. After I learned how to use it and what to except it is now simple to use and really quick to scan all bodies in a system.