You are never too old to learn piano or keyboard
Many people begin learnig to play piano or keyboard once they have retired. OK let’s face it, although the chances of becoming a world famous pianist may well have passed you by (but not necessarily) there is really a lot of enjoyment that you can gain from playing music.
What retirement does do is allow you the time on your hands to sit and practice, plus with that wise head on your shoulders you will also have the patience to gain a greater understanding of how to learn and how to structure your practice time.
You could maybe start out by learning some enjoyable and simple songs, gaining confidence and motivation.