The coordinates of a bird flying in the xy-plane...

The coordinates of a bird flying in the Xy-plane are given by x(t)=at and y(t) = 3.0 m - Bt^2, where a = 2.4m/s and B = 1.2m/s2.
Calculate the velocity and accelerationvectors of the bird as functions of time.

So, I know that I have to get velocity first and I got that but it seems like I am not doing it right...Please provide me with a extensive explanation. Thank you very much!