is a good place to start for evidence and see how it's formatted. Once you understand it you want to definitely do your own research (if you have a local university or anything that would be best, as they have research databases such as lexis.)
To see how debates are actually played out, understand it's definitely not what you're thinking right now. Successful debaters aren't the ones that sit and talk slow and persuasively (usually), speed and efficiency kills, you'll learn that soon. Look at some videos on youtube, shouldn't be that hard.