I hope you bought a hard copy of it, because if you bought it on Steam you have 4 installs left.
And yes, only game that comes to mind with a steeper learning curve is
EvE Online.
For controls, load a game (tutorial or ingame as long as you don't save afterward) and scroll through the Options/Controls and test every feature you come across, making note of hard to remember ones. You then wade through the ingame menu.
For making money, quick/easy/fun way is to capture ships (mainly fighters and cargo ships).The pilots will randomly bail if you slowly wear them down, so don't use hard hitting weapons for this. The less damaged the ship the more it sells for. You can also salvage weapons or get a new ship for yourself. The chance of the pilot bailing is kinda random. -edit- I recall from X3 taking down the shields really fast increases the chance of them bailing, but not confirmed -edit-
Once you get enough money, you can:
A- Buy some cargo ships and mine asteroids (see the egosoft forums for detailed information such as where, what ship and what equipment/software).
B- Buy some cargo ships and use them for trading items. You buy software for the ship that lets it trade (buy low, sell high). The ship will "level" and be able to travel further for better deals. Once high enough you can equip it to warp/jump/whatever over huge distances and rake in cash.
-edit- For the two options above, you can set them to automatically do such tasks while you go off and do whatever you want -edit-
C- Buy a cargo ship and buy low/sell high yourself.
But most importantly, Read The Egosoft Forums for tips. On a secondary note, if you find yourself ready to leave your computer running all night while your ships trade, just cheat yourself some money rather then adding the monthly fee of a MMO to this single player MMO in electrical bills.