raptorva: First off, nice draftmanship on the drawing - Such skills will stand you in good stead when your theoretical knowledge comes on with time.
You obivously have an interest in such things, so have you thought about investing a little time in doing some reading and learning some of the fundamentals which the above posters hint at?
Generally the texts aren't cheap due to their specialisation, but if you can, try your local library, or even purchase, a book such as this;
Introduction to Aircraft Design
You tend to find that the business of designing an aircraft is a huge task, composed of many comprimises influenced by factors as diverse as the size of your intended operating airports, efficiency of your engines, strength/mass/volume of your materials....the list goes on!
It takes many different branches of engineering to come together to reach a successful design - So start with an introduction, and perhaps start to hone in on the area which takes your interest and abilities. First and foremost though, you need someone with the vision to come up with a concept and set it all in motion!
Best of luck...it's an addictive pursuit!
