The buttons are called 'playbacks" or cuelist. (actually the playback is the button and the cuelist is what you control with the button),
Then when you edit your 'playback/cuelist' you will be able to store your light scenes into cues, Each square at the top of the edit window is a cue, so for now I think you have only one. But you can add up to 48 cues in a cuelist.
For each cue you can decide the "condition"= will it loop until you click again the button or will it "follow" to te next cue.
Then you can set the "delay"= how long the cue will be played before going to the next one ( only if the condition is set to follow)
And you can set the 'Fade"= that is the time it will take to fade from the current cue to the next one.
SO now the idea is to have one cuelist, with an alternance of orange mood and then lighting. Sett all the cues to "follow" and set random values for the delays... This will give the impression of a random lighting effect to the audience.
To use the API you need to have LPU-2 ( look on the sticker on the back of your unit (but I think you are using a LPU-1 that doesn't have the API).
The API is a specific network message that you can send to the LPU box from any other device on the network able to send UDP, TCP or OSC messages.
For example if you send the OSC message /pb01/go+ to the IP address of teh LPU and port 8000 then the LPU will make a GO+ action on the playback 1.
I hope this will help you,