As a PhD student, should I attend group meetings when they just make me feel bad?
Most commonly, PhD students are required to attend group meetings.  Often, the supervisor can make whatever rules about group meetings the supervisor wants to make.  Ask them.
The group meetings ought to help you become less inexperienced.  If it's not working well for you, tell your supervisor about it.  If that does not help, discuss it with another faculty member who is familiar with local practices.  You might also get help from a counseling office or office for international students.