I definitely had a couple of setbacks early on based on my previous experiences with space trading games... one time I saw a bunch of mining lasers that I thought were on sale at a much lower price somewhere else, bought like 150 of them, and then realized that I'd totally got it wrong and they were now all worth a fraction of what I'd paid for them. Oops! There goes all my money.
I also expected to be able to get in my ship and fly around manually, until I found out that you couldn't do that -- ship navigation appears to be done entirely through targeting objects and then flying towards them. Took me a while to get my head around that.
However, after my initial rush of enthusiasm banged up against my frustration at not knowing what I was doing, I stopped trying to experiment by myself and started doing the tutorial missions. It was all a bit foggy to begin with but as I proceeded through the tutorials I could feel it starting to make sense.
Having not played an MMO before I started to realize that there are differences with the "traditional" games I'd played before -- for example, since it is a persistent universe, you can't reload a save if you screw something up. This creates a sensation of "playing for keeps" which I think really adds a lot to the game. You actually do have to be careful before you make decisions, and have a fallback plan in case you screw up. For example, on a number of occasions I've gotten halfway through missions and then realized I'd left something vital at the station. I only had to do that a few times before I started really paying attention to my ship loadout before I launched. After a while you start to figure out what you need to take with you and what you should leave behind.
I've been playing it for ten days now and I'm still working through the tutorial missions. I haven't traveled more than about four jumps from my starting system, I haven't been in any PVP combat, and I haven't visited any low security areas. It seems that the key (so far) is to have ambitions, but not to get too ambitious too quickly -- you have to play slow and steady, then once you get comfortable with the basics you can start to branch out in whatever direction you choose. As a wise space pilot once said, "Don't get cocky!"
I feel like I'm in a good place with the game at the moment -- starting to feel comfortable with the mechanics, and starting to see pathways opening up for what I can try next after the tutorials. But at the same time I know I am only scratching the surface of what can be accomplished. I'm looking forward to finding out more.