Youtube experts: Youtube videoss :P?

You will need an editing softeware to do all of those things. Do you have mac or windows? Start with an easy program and explore it. Macs come with iMovie and Windows come with Windows Movie Maker. Play around with those programs and then maybe get a more advance one like adobe premiere elements. To make it switch to different clips you import media and cut and drag your videos. Most softewares have a speed editing option. and most have an audio spot where you can drag music.