The consensus here on SE MP&T is...
Go for it!
Among the various questions and answers linked here, you'll find a wide variety of viewpoints: encouragement, pitfalls, concerns, and so forth, but in general, you will find that the broad feeling across the site is "Yes, you can. Go for it."
NOTE: It's not always obvious from the title, but age is expressed as a concern in all of the listed questions.
What follows is a list of questions regarding beginning to learn when you feel your age is a concern. They are organized by subject matter; just know that an answer related to an area different from yours might still be the one you're looking for.
Late start as a general concern
Guitar
- Is it ever too late to learn guitar?
- Can one be too old to learn an instrument?
- Methodology to Master Guitar as an adult
- Muscle Memory and Age
- How realistic is it to become a professional musician when you start learning music late at life?
Piano/Keyboard
- Is It too late to start learning keyboard again?
- Is it too late for me to become good at piano?
- What to choose? Violin or piano?
- Adult learning to play popular songs on piano
- Learning piano in mid 30s
- Self-learning how to play the piano
- Is it possible for me to learn piano very very good if I start at this age (26) ? If yes, how long would it take?
- Learning piano by autodidact after getting older
- Jazz piano versus classical piano
- What instrument can an old guy learn if the main goal is to write music
- Becoming proficient at piano at age 30?
- ABRSM exams for adult beginners
Saxophone
Violin
- What to choose? Violin or piano?
- Restarting to play violin
- Learning my first instrument
- What is the right age to start learning to play violin?
- Can I learn violin without a teacher?
- What instrument can an old guy learn if the main goal is to write music
Viola
Voice/Singing
- Can one be too old to learn how to sing?
- How can I improve my voice?
- How to improve singing?
- Should I stop practice singing and switch to fingerstyle guitar?
Theory
Composing
- Is it too late to learn music theory and composition?
- What instrument can an old guy learn if the main goal is to write music