If you have investments but don't collect on any gains, interest, or dividends, so I have a 401k, roth IRA, and some REITs that I am not cashing out on until I retire, do I have to report those on my

No.  You only report distributions, conversions, rollovers. You will get a 1099R for those.

..."and some REITs" ?

 

As long as they are inside the 401k or Roth IRA accounts you don't report them.

 

But any dividends reported to you that are in accounts outside of those general types of special retirement accounts.....those held outside, they DO have to be reported even if you are rolling the Dividends back into the investment . 

 

Thus for a REIT held outside of an IRA/RothIRA or 401k (or outside of another pension type) ...you have to wait for your 1099-DIV, or -INT or -B and report that form on your tax return (REITs are notorious for issuing forms in March..but you have to wait for them before you file)