My father passed away 2 weeks ago and a friend of mine gave birth to a boy. I wanted to know if I can attend the brit mila or any part of it, if during the shloshim. I have friends getting married during my year of mourning and I wanted to know if I can attend any part of the wedding and if so what?

You can participate in the Brit itself but not the Seudat Mitzva. You cannot go to the weddings. If the Kalla will be seriously distressed if you do not go then you can go just for the Chuppa. Rabbi Yitzchak Grinblat