Halachik Conclusion:
Learn רא”ש פרק ג ס’ א who brings the different opinions whether we rule like Rabanan or like חנניא
https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=350
https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=351
https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=352
Learn רמב”ם ה’ שבת פרק ג הלכה ד
How do we conclude lhalacha?
Learn שולחן ערוך ס’ רנ”ג סע’ א