Any way to invest/double my money easy/safe?

No. Safe, easy, double do not belong in the same sentence. Anything that might double your money in the next year is very high risk, gambling rather than investing.

Stocks have historically returned 8% to 10% annually, with considerable volatility.

The realistic answer is to work more hours or get a 2nd job.

There is no such thing as a risk free investment.

However some things carry more risk than others.

There is a new website opening soon which allows people to invest tiny amounts in property, I guess it would work by using large numbers of people to buy the property then flip the property.

That would be kinda a very low risk investment. You can still lose though if the property is sold for a loss, which can happen.

So think of investing as GAMBLING. when the new site opens I hope they get the members they need will be fun to gamble tiny amounts less than $20 into property. Most people can afford to lose $20. Just wish they would also rent some - then the profits are even lower risk. But long term.

As jerry said, safe and double don't belong together. if it was that easy everyone would do it again and again and we'd all be millionaires. if you really want to double your money, go to the casino, they will give you the risk needed to make that happen. if you want income preservation and growh, consider investing in some equities. Personally, Id say go heavy in equities. being young, now is the time where you can afford a little more risk, apposed to creating a portfolio of fixed income assets.