文法的な解説をお願いします！

this is not a piece of advice to you I'm talking to myself for my practice of writing skills.
I've tried to put your sentence into GT. GT's translation is the next sentence.
Participation in extracurricular activities - be it a sports team or a rock band or a science club - is supposed to help kids make friends.
at first, I'll share the structure of this sentence with you.
1) subject :Participation
2) phrase which modify the subject :in extracurricular activities
3) subordinate clauses : - be it a sports team or a rock band or a science club -
4) verb : is supposed
5) object phrase (infinitive phrase) :to help kids make friends.
'Participation' + 'is supposed' + ''to help kids make friends'.
I suppose this sentence is the third sentence pattern (S + V + O).
I suppose that at least the meanings of the principal part of the sentence (S + V + O in this case) are absolutely essential.
:GT.
https://translate.google.co.jp/?hl=ja&sl=en&tl=ja&op=translate