The Bong hits 4 Jesus case[1] clarified that minors don’t have full first amendment rights since they are compelled to attend school, and government employees can punish them for their speech.

My memory is failing me for the relevant case name but I’m also fairly sure students don’t have full 4th amendment rights, again because they are compelled to attend school and the government employees are allowed to search them at any time

[1] https://en.wikipedia.org/wiki/Morse_v._Frederick