Back to school tips???

I’m starting high school at the end of the month. Does anyone have any tips on how to be as invisible as possible? Like I don’t want to stand out at ALL. 

I’m normally a talkative person but I’ve realized that whenever I open my mouth either nobody is listening, or they would rather me NOT and to save myself 4 years of embarrassment, I just want to know how to not stand out. 

Dont take this of me not wanting to be myself. I plan to express myself to the fullest while keeping to myself. I have no intention of changing my style, my personality etc. i just want to go to school, get my education and leave. 

Also, how do i shut down conversations without sounding rude??? Cause I don’t just want to ignore people but I also don’t want to be bothered. 

Please let me know yo, thanks guys