I remember being told they give you training material once you receive a CJO.is this true, because I dont think I received anything.

Not true. Just chill until your class date. If you have a training break, you’ll get your iPad, do your HR stuff, order uniforms, etc. You’ll have a little bit of studying you can do while on your break.

Should have got the “supplemental study guide E170/175” about 300 pages

There should be attachments to the CJO email in .html form. There is some literature there including the Supplemental Study Guide. It's not a bad thing to start looking through. Chapter 11 is the Limitations, and that's stuff you'll need to memorize at some point anyway. Not all of it, but speeds, etc.