Cheers, and welcome!
Yes, there definitely is exploration, and it works much the same as you'd expect from most 4Xs. The "no units" thing can be kind of confusing for sure, but basically you start out with a single scout point, and you can construct buildings that give you more scouting points.
During each turn, you can choose to scout by simply clicking on any area that is near enough to areas you've already seen. You then see a visual of one of your spy planes (each scout point represents one of these) flying out to the location and then back home.
So the "no units" rule can be confusing, because sometimes you are giving orders to units, ostensibly. But the thing is, there isn't a specific spy plane that you have to worry about health with, or individually manage, etc. Instead they are based out of buildings, which is the sole thing you have to manage the health and so forth for. The unit and the building are part and parcel.
This game actually has two levels of exploration! Overland exploration is fairly straightforward because you are using planes, not barbarian scouts or whatever. So water and so forth doesn't block you, which means that you have a lot more freedom to explore specific directions on the map if you so desire.
BUT there is also sonar exploration of the ground underneath the surface tiles. This is how you find a lot of the resources, particularly minerals and oils. It's also a way that you can find Thoraxian tunnels. Sonar scouting is a lot tougher, because the crews can't go as far and there are some other limitations. So you have better-than-average ability to scout overland, but then underground the scouting is harder than in most 4Xes.
Regarding scouting/sonar, if you have any unused points at the end of your turn, then it automatically uses them there, trying to expand as evenly as possible around your buildings. So the extent of your actual need to micro scouting is far less than in, say, Civilization. If you have a reason to go and explore in some direction, then you can immediately marshal all your scouting points and send all your planes in that area at once. You don't have to worry that one is stuck way off on the other side of the map like in Civ. And at the same time, the auto-scouting doesn't run any risk of you accidentally getting a scout killed or having scouts get stuck on one little continent or whatever. Much less management that way.
Any other questions on that, please do let me know.
