"Does anyone see anything that is prevent the regular plot from being plotted?"
Here are two bugs on the first two lines:
x=0:100:10; % start:step:end -> how many points are there between 0 and 10 with step of 100?
y=10*exp(-0.5*x)*cos(6*x); % you used MTIMES but you should use TIMES.
To use MATLAB you need to know the difference between array and matrix operations: