How do i go on a person's profil that u only know their nom d’utilisateur and don't know any clubs they're in ou anything?

Just insert their nom d’utilisateur at the end of the website address bar. For example, to get to my profil page, toi would type in:
www.fanpop.com/fans/saul_mikoliunas
It works for everyone, a long as their nom d’utilisateur is spelt corrrectly. So www.fanpop.com/fans/ The nom d’utilisateur in here.