When learning to play the keyboard, you will notice that a lot of musical pieces and predominantly songs are based around certain chords. So if you do know your basic chords you can already play most pop songs. I have put together some basic chord theory for you, so that you can start playing along to your favourite songs and improvise further on these. I do hope this is helpful for a beginner, however, feel free to comment below if anything seems confusing or if you would like me to provide any additional information.