I started out with C/C++ in college (that was the language they were teaching in). Then I picked up C# about halfway through college and didn't look back - I use it both at home for personal projects as well as at work (I'm a software engineer). I was able to pick it up fairly quickly (with help from a friend who learned C# on his own) since it's syntax is close to C++, and I had already been using C++ for 2 years prior.
That being said...(this is just my opinion) you should definitely learn a lower-level language such as C++ before jumping to a full OOP like C# or Java. You'll learn how things work under the hood, and in turn understand why some coding practices should be used while others should be avoided (e.g. using certain data structures in your program vs others).
Can you jump into something like C# or Java without knowing another language beforehand? Sure you can. That's up to you - but just be aware of how you're coding / using resources so that you're not wasting performance, or structuring a program in a way that makes it hard to re-use code from.