DB, if you know someone who has a piano or any type of electronic keyboard, get them to show you which white key corresponds to which alphabet letter. There are only seven different ones, after which they repeat in the same pattern. (This info will also be printed in any beginner's piano book, and I'll bet there are music theory websites that show it too.)

I shouldn't have described it as "playing a scale" because you don't need any instrumental technique at all - just tap the "C" key with your index finger, move to the key on the right ("D") and do the same, then repeat this for 8 keys (which is more useful than tapping only 7 - won't try to explain why!). The keys sit alphabetically, though the first note tends to be C, so it goes C D E F G A B and then repeats in that order all the way up to the top of the keyboard & beyond.

It's actually no problem once you try it. Or else get whoever owns the keyboard to do this for you. As Tootler has said, each series of notes (scale) has its own unique tone colour.