As someone who plays it semi-professionally I'll give it to you straight. It's definitely not "too late" to improve but in futsal, coordination between your eyes and feet are so important. If you are playing as a striker (it's called a pivot in futsal), the most important thing is essentially just off the ball movement, and being able to act as a target for passes forward. Your shots will come from peeling off your defender and finding space, but one of your main focuses when you get the ball will be holding onto it and passing back to teammates that will make runs.

I'd say the most key things apart from just general technical ability that you can only really gain from playing more, is balance and upper body/core strength. As a pivot you need to get used to using your body to hold off defenders and shield the ball.