Muneeb Aslam,
If you are beginning C# with no other coding experience then you need to learn programming; not a specific language. By that I mean the programming is programming, everything else is syntax. If you want to start out with C# that's fine, but learn to "Program".
If you already know how to code in another language and you just want to learn C#, learn the syntax first. Build simple programs like examples found in books. Make those examples work, first. Then experiment with the examples. Change them and find out how far you can take the example. If you make the examples work first before experimenting then if it doesn't work you'll know that it was your changes that caused it to fail and not a problem with the example.
Understand that there is nothing you can do using code that will cause a system wide failure of your system. The absolute worst case would be that you'd have to completely wipe your drive and reinstall everything back on to your computer; no hardware will be effected. What is the likelihood that you would do something that bad? Not very. You'd actually have to know a great deal more about programming and you're computer before you could accidently cause that sever of a problem. Experimenting with a textbook example would never get that bad. So, experiment all you want.
I teach computer languages at a local college and I give my students this same advice. Not only have they learned how to program but they also learn how to troubleshoot problems to the actual problem and not just Band-Aid the symptoms.
Good luck
