This is what you need to do to become a warrior:
1.Have gained the rank of apprentice.
2.Have gone on at least one hunting patrol with your Clan and mentor.
3.Have gone on at least one border patrol with your Clan and mentor.
4.Have been given at least one assessment by your mentor.
5.Have been given battle practice by a warrior and know how to use the Battle System.
6.Have been to at least one Gathering.
7.Have been an apprentice for at least a month.
When you have met all of the requirements, please pm your Clan leader and tell them that you have. They will hold your ceremony when they are ready. Also let them know what you would like your warrior name to be.
But, not only do you need to have met the requirements to receive your warrior name, but you need to be seen fit in the eyes of the other warriors that you deserve to be one.