Hi DJImport23,
Firstly, it will not be necessary to have 3 USB ports. You will only need one, to go from the back of the TTM57SL to your laptop. The CDJs will connect directly to the mixer with AUX cables, and will send the signal necessary to control Scratch Live, to the TTM57SL.
You will definitely need to ensure that you burn the control tone as a .wav file as if you were burning a normal audio CD that would be playable in stereos without MP3 capability, and you will need a control CD for each CDJ.
Here is a video about connecting up a TTM57SL which might help:
youtu.be
You will also need to ensure you select the correct inputs on input control selection knobs.
If you aren't getting a hold of the mixer until the day you have to do the event, it might be worth getting familiar with the controls and browsing the TTM57SL manual on the Rane website
www.rane.com
Let me know how you get on, and if you have any further questions :D