There seem to be very few Sec 1 Chinese / Higher Chinese Exam Papers available online, be it free or for sale. Similarly, Secondary 2 Chinese Exam Papers are equally rare.
The only resource online we can find is: https://padlet.com/hogtiggy/1FG_HCL
It contains Secondary 1 HCL MYE (Mid Year Exam) Revision Materials 2017, which is still relatively recent. There are also lists of Chinese vocabulary for different chapters, as well as tips for Chinese Oral Exam. Do download the PDF and Zip files while it is still online!
On the opposite spectrum, Secondary 4 ‘O’ Level Chinese or Higher Chinese Exam Papers are very common, almost every site has it, it is very easy to find.
For example, there is a 292 page PDF document on Smile Tutor full of free Secondary Four Higher Chinese Exam Papers from various schools such as Cedar, Victoria, or Nanyang Girls’ High School:
If you find any Secondary 1 or 2 Chinese Notes/ Exam/ Test paper materials, do comment down in the comment section below! It will help many readers who are searching for free Chinese Exam Papers (Secondary 1 or Secondary 2).