I had to start my game over, thanks to getting some bad advice from an online guide. When you play as a humble merchant, you start with two unarmed ships - a scout and a freighter. The guide suggested I sell one of my ships to get some starting capital. Specifically, it told me to sell my freighter. This would allow me to fully upgrade my scout ship, so I could run missions, and then use the money earned from missions to buy more freighters.
Since the guide described the missions I'd do as things like deliveries, salvage, and scans, I thought this sounded like a pretty good idea. There was only one, slight flaw. It turns out I'm terrible at missions. Every one I tried required some form of specialized equipment, or more cargo space than I had available, or it needed to be completed in less time than I could manage. I can see how the guide's strategy might be effective, if you're already familiar with the game, but to a total newbie, it was pretty worthless.
Unfortunately, I was stuck without a freighter and with no easy way to get it back. Thus I was forced to restart.
At first, I figured, since I was restarting anyways, I might as well give one of the more martial setups a chance. It was a complete disaster. I chose to be a brave Terran defender, and as soon as I finished flight school, I was called into action. AIs attacked a human installation around Neptune, so of course I leapt to its defense. Using my new piloting skills, I was able to take down one of their drones, and then was immediately destroyed by a second drone that snuck up behind me.
Ordinarily, this would be the point where I shake my head ruefully and reload the game, but it turns out that X3: Terran Conflict's save system is really unforgiving, especially to people who spend a lot of time in combat. It will autosave whenever you enter a starbase, but not when you leave, and you can only manually save while you're docked. So when I died, I lost more or less all of my game.
Thus it was back to being a humble merchant. Building up wealth through trade is a slow process, but I like its steadiness. My plan is to explore the various sectors, finding new markets and learning where advanced equipment and ships are sold. Once I build up enough of a nest egg, I'll try missions again, but not before I learn to use jump drives, which from what I gather is essential equipment for any time-sensitive mission.
I feel a bit guilty about abandoning the galaxy in the face of the AI threat, but I was really ineffective in combat. Sorting through menus is more my speed.