Impulse Response and input signal

Please, I need help with these codes.

In the first one I have to find the spectrum of the impulse response given. Then find the magnitude and fase of the spectrum and graph them.

In the second one I have to calculate x(n)*h(n) knowingh that h(n) is the impulse response and the input signal is x(n)=e^3u(n), then graph y(n)