With some memorization and patience you can learn how to read sheet music adequately. Use your learn-at-home guide for tricks to remember helpful hints like DO RE ME FAH SOH. Learn the key of C first, which is the entire combination of notes. Once you learn C, begin to familiarize yourself with the other 12 keys.
Learn the meaning of tone, rhythm and the fact that keyboards record what you play. These facets are considered the three types of memory within the keyboard.
Begin by choosing rhythms that are familiar to you. Use the memory tricks from your do-it-yourself guide and play progressions in the style of popular songs. Practice one song from different varieties of music like pop, rock, country and jazz.
Find a few other beginners online who perhaps are just learning drums or the guitar. With the instruments, the guitar will do chords in C major, you do the C major scale, and the drums the rhythm patterns. Since you are all just starting out, there's plenty of room for trial and error with your new band.
See if anyone knows how to play the keyboard who's available to give you some pointers. Pay for lessons if you can afford them. Practice daily and take it one day at a time. The keyboard is like a one-person show so stick with it and in time you will be a performer.