Did a little smuggling and cargo running out of Sothis at the beginning of Horizons.
My only advice is, whatever you do, don’t accept any smuggling mission which says “information will be available when you arrive in Ceos”. These are just a long-haul cargo missions in drag, with the added bonus of possibly getting blown up at the end of it.
Otherwise it’s good earning because Sothis is so remote. Something to note; a typical hauling round trip will take around an hour, so it becomes something of a time sponge. Also I was running an Asp Explorer at that point so your experience in a Cobra will probably vary.
There are or used to be a few systems where you could get very good money smuggling. Sothis was popular as it had sort routes. Yes you can make lots of money.