I too, bought X3 recently. Its certainly a bit confusing at first, but have you read these guides yet m8?:-
http://forum2.egosoft.com/viewtopic.php?t=100641
There's a lot to take in, granted, but if you stick with it, things start slotting into place eventually.
Get the abandoned Toucan Hauler first, its pretty easy, then dont bother keeping it, your reputation wont allow you as yet, to take multiple passenger transport missions anyway, so its of next to no use to you at this stage.
Sell it and buy a few upgrades for your Buster. Then, again, read some of the guides to trading etc and slowly start earning cash. I've been trading in space fuel, energy cells and wheat at the same time I've been reading the bulletin boards and transporting single passengers around between stations and systems. You can make around 2000 credits with each run.
It's worth printing out a few of the guides in that link so you can refer back to them at your leisure.