I picked up guitar because of a heavy influence of my Uncle Marlay. He played really well and I really liked him, so it just clicked. I also learned clarinet when I was in grade school, sang in he Dayton Rotary Boy's Choir, where I was given extensive vocal training, and dabbled with several other instruments for fun.
I told my kids, it really doesn't matter what you play, just play something and put notes together that please you.
My kids all sing and play several instruments, some better than others.
I play guitar, I have played it since I was about 10 and I am still a complete amateur. I don't mind, it makes me happy and I play what I like to listen to. I have spent more time recently expanding my knowledge of music theory, but you don't need to know theory to have fun and enjoy the experience.
I will say, that when I learned the circle of fifths, and that fifths were discovered by Pythagoras music took on a completely new meaning for me.
Today you can learn how to play just about anything for free on YouTube, you have no excuse not to learn.
Places that really help me: