Well, there is alot to cover.
My first advice is to see if there is any place near you that offers classes.
Beyond that, learn to project emotions with your face and body, not relying souly on sound. Make a list of emotions, stand in front of a mirror and give it a whirl.
Clowns rely heavily on physicality so any movement studies would serve you well also.
I also tell students to look at a normal object and think of unique ways to use it. This helps with clowning.
Watch clowns.
YouTube will be a huge asset for you.
John Quigley is my absolute all time favorite. He does/did alot with Cirque Du Soliel and he really has great vision.
What type of clown do you want to be?
There are several archetypes and which one, or combination of, you want to be will factor into how you create that clown character and "play" your clown.
What style of performing with it as well?
Festival vs. trad circus vs. cont circus creates alot of difference with how and what you will present.
I know the public library here has a few good books about it under the "performance art" category.
If you can think of more specific questions, that might help you get more helpful answers.
