Horizontal and Vertical Acceleration?

A symmetric projectile spends a total of 20 seconds in the air. It reaches a peak height of 8 meters. How long does it take to reach its peak height? The projectile has a range of 80 meters. What is its horizontal velocity? What is the projectile’s horizontal acceleration? What is the projectile’s vertical acceleration?

For how long it takes to reach its peak I got (8m)/(20s) = .4m/s

Horizontal Velocity I got (80m/20s) = 4m/s

How do I find the horizontal and vertical acceleration?