Ways to improve my vocal ability?

Wow! You actually sound really nice! Just stay away from dairy products, since they create phlegm. Also, don't drink hot or cold drinks before you perform, they irritate the vocal cords. Caffeine is also bad, especially from sodas and coffee. Keep it up, you sound really nice. Not that it doesn't sound good, but try singing from your diaphram (center of your torso, just below your chest). It will add intensity. You're doing great!