Make Music Already!
If you're interested in learning to play music, don't let anything hold you back.

True, not everyone has the natural ability to hold a tune, but even the haughty laugh of a woodpecker is music to the ears of other woodpeckers. Especially for those just curious about what they may be able to do, or children eager to explore the creation of sound through math and mechanics, the biggest barrier to starting is often an imaginary wall we build ourselves -- "I can't do that."
This wall has many bricks. Here are a few you might recognize:
I can't afford the instrument.
I can't afford lessons.
My brain isn't capable of doing it.
I'll never be as good as ___.
As in most challenges we face, managing expectations goes a long way. If you're starting from zero experience, and hoping to become Mozart in 3 years, you're doing it wrong. In the interest of brevity, consider these quick answers to the above aspects of "I can't do that."
1. I can't afford the instrument. Which instrument? There are many different instruments that are capable of contributing music. If you can't afford a baby grand piano, what about a harmonica? There are also rentals, second-hand shops, bartering arrangements, and borrowing from others. Some instruments can be made. Some we were born with.
2. I can't afford lessons. See the above regarding affording the instrument. In addition, there are many self-guided instructional books and videos for just about any instrument. And not all musicians take formal lessons. They can be a benefit if you want to become an expert, but aren't a guarantee that you will enjoy it any more. If doing something that you want to do and getting enjoyment from it is the goal, just start.
3. My brain isn't capable of doing it. Give your brain a chance to become capable! Much of mastering an instrument is muscle memory, which can't be formed if you don't physically begin. And don't be shy about relying on supports until you get there. Any other craftsman relies on tools to achieve their best work, why shouldn't someone playing music?
4. I'll never be as good as ___. Hopefully not. Hopefully you'll be as good as YOU. And remember, as hinted briefly above, there are many voices in a chorus and many instruments in an orchestra. If they were all the same, there would be no point. Skill and talent and grace in technique are things to strive for, but not comparability.
So, what song will you sing? What melody will you compose? What harmony will you fulfill? It all starts with a single note. Play it.