I made a fortune space trucking with the economy scanner, but be forewarned that to make real money hauling goods you’ll need a ship with a lot of empty cargo space. I’d also recommend upgrading the warp drive in your ship so you can travel to any color system, as it opens up your buying/selling options considerably.
There is a really good Steam Community Guide on the subject assuming nothing changed in the Beyond update. In a nutshell, the economy scanner shows you all the economic information for star systems in the star map view, allowing you to determine where to buy and sell goods to create your own trade routes and make some mad money.
You trade goods in loops depending on the industry of the systems involved, for example Advanced - Scientific - Trading (then back around to Advanced). The scanner not only shows you what type of industry is in a system, but the level of supply (you want to trade in high supply systems like Wealthy, Opulent, Affluent, etc.) and the margins for buying/selling versus the galactic average (anything higher than 20%/60% will make you money).
I’m sitting on 175 million units, and I’ve had even more in the past, the vast majority of which I received from running trade loops while exploring and scouting for S-Class ships to own.