To find a scale on a piano, you need to know the name of the scale and its starting note. Once you know this information, you can locate the starting note on the piano and play the scale by following the pattern of whole and half steps. For example, a C major scale starts on C and the notes in the scale are C, D, E, F, G, A, B, C. To play this scale on the piano, you would start on the C key, play the next key (D) with your right hand, then the E key with your left hand, and so on. The pattern of whole steps and half steps for the C major scale is as follows: whole, whole, half, whole, whole, whole, half.
You can also find the scales in piano sheet music or online resources like youtube videos, online piano lessons and piano learning apps.