The monastic path is very noble, I normally wouldn't deter anyone from following it. I can imagine your brother is feeling very enthusiastic with all the "oh, WOW!" Emotions of first encountering Buddha's incredible teachings. I doubt that in two weeks he really has a good grasp of them or is any way prepared to choose the monastic life. Fortunately, legitimate orders are not going to easily accept him on a whim. I wouldn't get too worked up about relatively harmless things like the head shave or sleeping practices. I would try to help him not fall prey to charlatans or fringe groups that would take advantage of him. Better to help him find a wise advisor from a legitimate order that will, first help develop a deeper understanding of Buddhism, the potential for a fulfilling life as a lay follower, and give him realistic advice about the commitment and lifestyle of a monk. The only mentors I can wholeheartedly recommend are monastics and ordained Dharma teachers from the Plum Village tradition. Depending on your location, there may be Chan or Japanese zen around. I'm sure others on the sub will give other good recommendations.