You can set the bullets angle when it's created to make it fly up instead
As for rate of fire, make a variable for reload and set it to 0
In the event where you fire a bullet make a subevent that says if reload=0
so it will only fire if it's 0
In the same event set reload to something above 0 once the bullet is fired
Finally make an every tick event and set reload to subtract 1 if it's above 0
Hope it makes sense:)