Here are the links given below where you can find sample papers:-

http://cbseacademic.nic.in/web_material/SQP/ClassX_2019_20/Science_SQP.pdf

http://cbseacademic.nic.in/web_material/SQP/ClassXII_2019_20/Mathematics_SQP.pdf

Above given links are for the subjects maths and science. From the same link you can find sample papers of other subjects.