There are two basic modes of play: survey mode and move mode. In move mode, Xconq automatically finds the next unit that needs orders, gets it visible on your screen, and selects it for you. Then you can left-click on a destination or target, and the unit moves there or attacks, whichever makes sense. Move mode is very fast to play, although the bouncing around from unit to unit can be disorienting. In this mode, the selected unit has a moving marquee hightlighting it.
In survey mode, you click on a unit to select it, then right-click on a destination to move it. Then you have to find another unit and do the same. This mode is better for careful play, although in a complicated game it can be difficult to find all the units that can be moved.
Experienced players will usually shift back and forth between the two modes. For instance, you can start out in survey mode, move all the units you can see in the sea, then switch to move mode, which will find the nearest unit not moved and select it, then switch back to survey mode to give it orders.
The selected unit is indicated by an outline box - solid black&white lines to indicate that it can move, dark gray to indicate that it cannot move, and gray to indicate that it cannot do anything at all (at least during this turn; some types of units may only get to do something once in a while). If clicking on a unit image doesn't have any effect, then it's not a unit that belongs to you.
Some games allow you to fire at units from a distance. To shoot at another unit, position the mouse over the desired target, type the fire command `f', and the selected unit will attempt to fire. If the target is too far away, nothing will happen. 'f' can only fire at units that you actually have under observation. Use `Control-f' to fire into a cell where you can't see anything.
To jump ahead to the next turn, do the menu command `End This Turn' or the key `return'. You may have to do this if some of your units still have action points, but not enough to do any of the things you want them to do.