Matlab Simulink code for QPSK Modulator

Given 2 modulating message signals (I and Q):
SI(t) = 0.5 sin(2pie 10t) + sin (2pie 20t )
SQ(t) = 0.7 sin (2pie 15 t) + 0.3 sin( 2pie 25t )

carrier frequency , fc = 500 Hz
sampling frequency, fs = 63 kHz
using QPSK Modulator

What is the matlab coding for the simulation to obtain the plot of the amplitude spectrum of the modulated signal (QPSK output)?

I need to obtain:
plotting of continuous and sampled of I and O signals
plotting of I and Q modulated signals
plotting of QPSK signal
plotting of amplitude spectrum of QPSK signal
any sample? or instruction on how to use the matlab?
Thanks for helping...