I want to start filming pranks so what kind of equipment do I need?

So I have a camera not like an expensive one but just a Nikon cool pix and I have an iPhone I made a DIY lavalier microphone it records audio so could I have my phone in my pocket and the mic on me record the audio while my friend is recording me far away mad then could I take that audio and lay it over the video oh and I'm using a Mac as my computer and suggestions on what I need to get and don't tell me that I need this $1,000 I can't get that but yeah any suggestions would help, what do I need to start filming pranks?

Last but not least definitely a fake stupid looking $10 camera for the effect of some guy filming.

A good insurance policy is something to be considered.
Your idea of editing in the audio is possible. Mac has an editing program that would do that I think. "IMovie"