Start with something like this:
dv1 = @(g,c1,v,m) g-c1*v/m;
v(k) = v(k-1) + dv1(g,c1,v(k-1),m)*h;
Plotting one point at a time is generally unnecessary and cumbersome. When you plot single points that way with the default linestyle, they are not connected by lines. You could make the dots themselves visible by specifying a marker type other than the default, but storing the results and putting the plot statement outside the loop avoids the hassle and leaves you with vectors that can be used for other things if needed.
It's also generally good to avoid unnecessary while loops, using for-loops when the number of iterations is known beforehand. This avoids any chance of mistakes or unpredicted scenarios that could cause the loop to not terminate. Such an oversight isn't really a big risk with something this small, but it's something to keep in mind as your code gets more complex.