The progression in Elite is really up to the sort of things you like to do (shoot, trade etc). Here’s what I did and still keeping it varied (I’ll come back to edit this for more detail, but wanted to give the gist of it now).
Progression Steps For Money!
Step 1. Sidewinder bounty hunter. Get a Warrant Scanner and equip for some gimbal pulses. Go to either a High Resource Extraction site or a Nav point in a non-anarchy system and find the local police ships. Follow them around until they (inevitably) find a smuggler. Join in the fight, unless the system police look hopefully outgunned (more usually turn up). Anyone around even before the fight, scan and if ‘Wanted’ then make sure you do your KWS scan for extra money. If fighting a biggie, just sort of skirt the fight but still join in a bit, just don’t get blown up until you can upgrade a few things in the base sidey. You’ll make good bounty money this way.
Step 2. Once you have enough for a Cobra MkIII with a good jump range do some ‘rares’ trading. This is really a combination of long haul small cargo stuff and is fun for a few loops as it is a way of exploring. Rares are high value, um, rare goods that spawn at a very limited rate but are worth a lot of money but only if you transport them 150ly at least (as in their sell value goes up the further from origin). To max out this you fly a loop with two hubs and go back and forth getting a lot of money relatively quickly, usually about 1 million every 45 mins or so. Remember, you just need to go fast and large jump distances with the Cobra, so fit it out with cargo pods and (if feeling greedy/brave) no sheilds and no weapons - you can just run and go!
Have a google, or use this route map. Find out from where you are if you start top or bottom, or just make your way over to any of the steps. The bold black route is the easiest or depending on how much cargo space you have (do max it out though).
Quick Key: Buy at the hollow circles, sells on the $ circles, otherwise get jumping with my tip being never wait for rares, just dock and go!
Step 3. You should now be rich. The choice now is either to go mining, bounty hunting or traditional trading for more money. For mining a Type 6 is good to play with, for hunting the Vulture is worth saving up for. For trading, a type 6 or even hauler steps are fine, and with ‘slave trading’ producing the most money (not that I’ve ever done that, but hey…).
Step 4. If you get tired of money and have tried trading (two system bulk stuff makes huge amounts with a large ship but can be dull after months ) then check out exploration. An Asp could get you to the center of the Milky Way, plus you scan as you go and make money on your return for the scan data. The repair robots pretty much mean you don’t need to see civ space for a long time if that’s your thing.
Alternatively, check out the community events - Frontier seems to be loading them with ‘making money’ recently, so if the grind gets a bit much then they are worth the distraction. The recent Horizons update seems to also increase the return of missions, so also feel free to ignore all the above and just take the missions early on, it’ll certainly get you to step 3 as well.
Note: I’m no expert on this, I think people like @Navynuke99 are way ahead of the game than me.