my sister always buggs me but then when i say sarah she goes and tells on me and i get in trouble?

Its an age old dilema. Ignoring her would work best but thats almost impossible to do if she is annoying beyond reason. What you need to do is tell on her before she tells on you, sounds sucky but this is how it works:

You're doing your thing, she starts bugging you.

You give her 1 polite warning that you don't want her near, that she will get into trouble if she stays around longer than 5 minutes.

5 minutes later if she is still there slowly walk out (without talking to her) go to one of your parents, wait patiently until they're ready to listen and say calmly, clearly and politely (so your sister can hear you too) "I'm trying to play quietly but Sarah is making that impossible, can you talk to her when you get a moment?"

From here if Sarah complains you are in a much better position and you can always use this trick again if she starts playing up.

i do not know what you mean by sarah and how that gets you in trouble

just talk 2 her or tell your parents.

talk to somebody