Cosmicdestroyer I figure I could offer some designs for you to test against and help build up your skills!
First off, lets start at the smaller end of the competitive spectrum: 500k ships! (As stated by @Alpha, most competitive designs range from 200k - 2 million. It goes a bit lower for Domination mode, where smaller ships rule).
So, here's my first challenge for you!:
Your goal is to beat this ship with another ship that is no more than 500k credits. Once you beat this one, I have another tougher 500k ship for you to beat as well.
This should hopefully allow you to get the feel for some of the key aspects of building, before you move onto larger ships!
Good luck!