Hey! In order to report people for things you can't sr for, you need video evidence or screenshots. In the case of teaming, you will need clear video evidence. You can find more information about evidence
here.
To report for Java, visit
this page for info and
this page to report. To report for Bedrock, visit
this page.
Also, next time you create a thread with a question like this, be sure to post in the correct category, called "Support"