Before I say anything I'd like to point out that you're in college so you've got time on your side. . . which is to say if you blow it up you have plenty of time to make it back.   Also, kudos on having 500-1k per month to invest.  Most college kids I meet can't even afford a burrito at the end of the month.

Onto your questions:

Before I start, this is not investment advice and should not be construed as such.  Any purchases you make are on you as are any profits or losses.  

Gold is a good asset but you have to be careful purchasing it.  Physical metals are unregulated and often sell for ridiculous premiums (read 50%+).  The worst I know is a site that marks up their metals 400% and through some shifty marketing gets away with it.  If you go physica0,l stick to bullion and don't pay more than 3% over spot.  If you're in the US and need help with this let me know.  If you're outside the US just remember,  no more than 3% over spot.  Ever.

Real estate-  yeah, that's a tough one.  Aside from the necessary capital you'll need to know what to look for and where.  I know people in real estate and it's a heckuva learning curve from what I've seen.

Equities- well an old school trader one said to me "The stock market was designed to create wealth and the forex market was designed to take it back"  Obviously I mention this for the first part.  Having the right stocks is essential.   If you know how to pick stocks, cool.  If not, I'd ask for help.

Crypto-  not sure I'd call it a safe haven asset yet, although it has a similar function to gold and is easier to use when transacting business than the barbarous relic. I love crypto, but I still don't recommend anyone put in any amount they don't want to lose.   It's probably the highest risk of everything on your list.  That being said, it's your money so it's your decision.

Regardless of what you do I'd stress test the portfolio. (EDIT: If you need help with this too, I can probably run one for you)

Let me know if I can be of further assistance.