What can you put your 401k in that is reasonably safe? Money market, cd's,gold?

Your plan probably has specific requirements.

For general info., check out Vanguard or Fidelity.

Most plans have a "Retirement/Preservation Fund/Trust" of some sort.  They typically are invested in a combination of Money Markets/Cash/Short-term Treasuries and sometimes Gold/Silver.  They typically return in the 3-5% range per year and when combined with an employer match actually work out to be a fairly decent rate of return.

If you leave your job, you can roll your 401k into a self-directed IRA and into any number of funds, stocks, ETFs or whatever.

Rules? Fund Manager? Lots of variables.  Some won't even let you trade but every three months. Some only let you pick from 10-12 funds. etc.

I don't have one but IRA's and day trade stuff. Like last night double and triple short ETFs , tonight I'll probably buy GM or fanny.  I don't take it too serious 10-20 minutes a day.

If you can't move it money market is were it's at long term. Interest rates will be astronomical in future and market will crash IMO.