If you're looking for good trading routes, try https://eddb.io/trade/loops .
Set the max hop distance to the maximum laden jump range, set the minimum supply to 1000 and, if you don't mind trading imperial slaves, set the minimum demand to 0. It should come back with a load of options over 2000 per loop per ton. When I tried there were some over 3000.
With one hyperspace jump and really short distances to stations it should be possible to get about 4-5 loops per hour for 800-1000k per hour. Maybe more. Then when you've got about 20million you could get a type 7 and double the amount you earn.