Are Physical Metals a good Invest?

Physical metals are actually a pretty crummy investment and at most a small part of your portfolio, if you include everyone. A well-diversified stock portfolio (without metals) will serve you better in the long run.

You can trade equities (stocks) and futures (commodities).
 
However, it depends on how your investment. In this case, stocks and bonds are the options. However, products are constantly changing. For example, precious metals are good during the crisis (the crisis of European economies and bad), because investors are choosing as a refuge.  

This means that people will buy the physical metal rather than paper currencies. In other words, when people are selling dollars and buying gold, the dollar goes down, and while the price of gold will rise. Dollar and gold and inversely proportional.
 
Therefore, 

It is better for you to buy shares of large companies seeking long-term growth. Take, for example, companies of cloud computing, technology companies, ... Etc.