LB -yes, everyone agrees that circumcision is a must for all Jewish boys. It must be on the eighth day unless the baby is sick.
Upsherin is a minhag and it does not have to be done. I think it was actually a Chassidish minhag that has become very popular in most or many Frum circles today.
In Israel, it is almost unheard of not to do one. I have a friend who didn’t do it because her husband is Yekkish and it’s not a Yekkish minhag. She had her son start wearing a yarmulka as soon as he got his first haircut even though he was under 3 becuase she was afraid that people would think he’s not Frum if he has a haircut but no yarmulka (since in E”Y, everyone waits to do the haircut till age 3 which is also the age that boys generally start wearing a yarmulka. So it is unheard of for a Frum boy to have his hair cut but no yarmulka).
On the other hand, I once worked with an autistic 7 year old (approximately – I don’t remember his exact age) whose parents deliberately kept his hair long because they wanted people to think that he was 2 so they wouldn’t realize that there was anything wrong with him. Personally, I just thought that he wasn’t Frum until someone explained to me. He didn’t look like he was 2 – he just looked like he wasn’t Frum.