Colour look's good ~ can see the paint ripples you mention, but that's just where it's gone on a bit thick & it's run that's all. Practice make's perfect.
Regards to the sanding it all depends on how smooth you want the finish. Sometimes it's not necessary to sand after you've rubbed down & primed then sprayed your end colour. Really up to you.
If you do get paint runs though on your car parts after spraying the final coat you can always rub them down with wet & dry sand paper, then re-spray.