The "Manual" link at the top of the page, of course!
It's actually quite helpful, isn't too dry, and is practical. It doesn't read like a manual, it reads like tutorials.
There are essentially two types of conditions--they're all variations on those. Every Tick and Trigger Once. Every tick is something that is a process or continues over time (moving an object over time, for instance). Trigger Once happens when a certain condition is met once. You'll use other things like "is X> 40" or whatever to narrow it down. You can add "trigger once" under "system" to a normal event to make it happen once while that condition is true. Those two types of actions can build a game--and eventually you'll get fancier and add loops and arrays, etc.
But read the manual, check some tutorials, look at the example files that come with C2. It's all helpful stuff.
BTW, before you do it any other way, do all of your movement or anything that happens over time *dt (multiple by delta time). This will make your game smoother and framerate independent--which you want.
Every Tick | Set X to (X+20) works, but now how you want. Will run differently on each computer.
Every Tick | Set X to (X+150*dt) works how you want. Will run the same on any computer, is smooth.