Check your planning menu, it gives you ideas for what to explore to find. Also gives you specific spells to get, etc.
To some extent, this is what the game is: it's big, it's open, you have to set your own goals to help you reach your long term goal of killing the overlord. If you wander through every room in every random building, that's going to be boring as heck. It sounds like you just went into some sort of random office building or something and wandered around scavenging. To some extent you need to meet the game halfway and learn to scout effectively by using the maps, etc. Which is mostly just about observation and looking at the tooltips, etc. But also the intro mission kind of covered that, too.
There are, literally, thousands of random buildings in the world. You could spend 10-30 minutes completely exploring each one. It would be boring and pointless. But there are stashes in each one, and you can quickly locate those, get the goods, and get out. But that's not really the main thrust of the game either, because that's not helping you to actually get more spells. It's just helping you to get prepared for missions (get more platforms, upgrade stones, etc).
When it turns you loose in the world map for the first time, it pretty well says most of that. It also suggests you check your planning menu and decide which long-range spells to pursue. If you just wandered off into buildings instead of doing that... well, that's valid to do, but if you don't enjoy it I suggest something else.
I'm not trying to be flippant, but I'm pretty tired and it sounds like you are as well. At any rate, it's kind of like AI War: you just looted some random mark I planet that had nothing on it, simply because you saw it. Not very useful! I mean, sure, some
use -- but not as much as the effort you put into it. AI War galaxies are miniscule compared to the world in AVWW, so you have to pick and choose your targets even more carefully. Not because the AI will Get You if you don't, but because you won't get much done if you don't.
Volatar: Combat difficulty adjusts the speed of enemy attacks, as well as damage dealt. Sounds like it's a bit high for now.