Every serious programmer should know C/C++ because they are used everywhere. On the other hand, they might not be the easiest languages to begin with. Script languages like Python or Ruby are gaining popularity and are supposedly easy and fast to program with. Java is also quite popular and easy. Or you could try something very different. For example, Haskell which is a functional programming language (C, C++, Python, Ruby, Java are all imperative languages).
It really depends on what you want to do. Just choose one language and stick with it (one I mentioned or something else). After you have learned one language it's easier to learn another. The Internet is full of tutorials you can read/watch to learn. Here's one for C++...