This is not intended as a criticism of any advice you are receiving, and is not intended to be insulting to those giving it...
The journey is the thing. We were discussing yesterday that after a while the game can become stale, and it can because with respect the activities are shallow and repetitive. My typical example is that once you know how to destroy a pirate lord that part of the game is over because every pirate lord is exactly the same.
I would advise very strongly not going down the road of trying to earn x credits per hour, because at that point the game has become a job. Easy for me to say I suppose since I have many billions of credits, but remember I've been playing a while. And one of the reasons I have billions of credits is because there's nothing to spend them on. I personally like small or medium ships, so buying and outfitting a new ship costs very little and the credits it takes are re-made before I know it. So do activities that you really want to do and the credits will flow anyway. Most activities pay very well. I have never needed to farm credits - the only farming I ever did was going to biological sites to farm grade four materials which I did once or twice and that was the least fun I've had in the game by a long shot.
If you are interested in exploration, I'd recommend exploring for yourself, not exploring a known route. You don't have to go that far, a couple of thousand light years from the bubble and you are on your own, completely virgin systems everywhere. Scan them, map them and they will forever have your CMDR name next to them in the system map - nobody will ever see it, the galaxy is vast and less than 1% explored. And by the way, the Asp Explorer is actually a very good exploration ship. You'd never guess it from the name.

I got to Elite in exploration in mine. I do now also have a Phantom, which jumps maybe 4 or so Ly more, but that's only really important if a) you want to reach systems a long way away or b) when you are doing the last few thousand Ly back home to sell your data.
And exploration pays fine. I did a short trip recently to test out Odyssey, maybe a week or so, and not many hours played at a time and I got over 250 million credits, and I wasn't trying! Didn't even scan whole systems, just went for cherry picking for the first time in years to prove to myself how easy it is with the FSS, mapped only ELW's, WW's and Ammonia worlds, and those only if they weren't too far out... Do it properly, scan all the high value high metal content worlds, scan whole systems for the bonus, scan only unscanned systems (they will be your first discoveries and give more bonuses), map valuable bodies... Learn how to use the FSS effectively, it's not hard, map bodies with less than the recommended probes and get bonuses...

And after that you'll know whether you enjoy exploration or not, and you'll probably be Elite in exploration also.
Anyway, that's my suggestion, and it's a suggestion only. ED is a game, you're supposed to play it for fun, and IMHO if credits or ranks or a particular ship, or a fleet carrier or whatever becomes the reason you're playing it I'd suggest frustration and burnout, not to mention resentment when FD nerf something that you felt was helping you get somewhere quickly will be the end result.
Lecture over - now go and have some fun.
