Bit bitcoin now is more investment instrument, but not a currency as it was in the beginning. A lot things were done for bitcoin future, but this is not enough...

Can somebody tell me about MyEtherWallet? I heard that it is unsafe and you can lose all your money. But what if I won't give nobody my private key? How can another users get access to my coins?

You can't be sure in currency security. But you should know, that first bitcoin code has bags and technical problems. Community is always working to improve bitcoin security. And, as you know, nobody interested in its safe and reliability as much as coin holders. So, eben if something will happen with code, it won't be a problem.

It's never too late to start doing something. The same would be say about bitcoin. Today's price is $ 11,800, but two weeks later — $ 15,000...