When is anybody going to learn, it's the Big 4.
There are 4 Big Ships.
https://i.imgflip.com/1xtbzu.jpg
1. Anaconda - not that hard to acquire, can be obtained and outfitted in 15-18 hours once Felicity Farseer is unlocked.
2. Corvette - Federation Rank Locked - can be obtained in 7-10 days, assuming you only run Federation missions.
3. Cutter - Imperial Rank Locked - see Corvette
4. Beluga - also not hard to acquire, can be obtained and outfitted in 6-12 hours once Farseer is unlocked.
Any "grind" is purely in your heads. This is a game about being a space ship pilot in the 34th century. And what do space ship pilots in the 34th century do? They fly space ships, obviously, but they do so to make money, to buy more space ships, to make more money, to buy more space ships, so that eventually they have no more space ships to buy, and no more need to make money, and sail away, on a white ship, ne'er to be seen again.
Just play the game, rank and credits will happen. I played for around a month, just doing odd jobs, experimenting with various things, and ignored those Federal and Imperial Navy missions for quite some time. Then, one dayI took one because they kept bothering me with these, and the pay was really decent - and I found out what they were for, and kept taking them - and jumped up about 5 ranks with each Navy. Dots connected, it didn't really take that long at all for me to hit any given rank - from Ensign to Rear Admiral in a weekend, from Baron to Duke in 4 days - and that was a weekend of doing what I wanted to do anyways, and a four days of doing something I wanted to do anyways - and that was Just Play Elite.
There really is only so much to actually do - missions are limited in complexity - fetch something, deliver something, blow up something - pretty much sums it up. But it's entertaining to fetch things, deliver things and/or blow things up in a neat looking space ship, in a nicely detailed 3d environment, even if it is excessively beige. But then, some folks are entertained by solitaire or putting the numbers 1 through 9 in boxes of boxes so no two of the same digit is present in any row or column.