It’s been many, many years since I took my Intro to Anthropology course at uni, but my dusty memory is that a ritual is defined as a ceremony or series of acts which are performed in the same order and manner repeatedly. An example is a funeral service where the same actions and words are repeated each time the service is performed. A wedding ceremony is another example. Sometimes this word is used to describe less formal events, like a bedtime ritual, but the key feature is that it is performed over and over in the same way.
Therefore, I am having trouble seeing how completing a pilgrimage once in a lifetime could be seen as a ritual. By definition, it is not. I see it more as a type of retreat, removing oneself from daily life in order to focus on spiritual or religious matters, or de-stress or whatever. Within a religious pilgrimage, there are rituals, certainly, such as a blessing before departure, or others that other posters have mentioned, but not the pilgrimage itself.
So my advice would be to first be really clear as to the definition of the topic of your paper. Maybe my definition isn’t correct or current, but you should be sure to be on the same page as your class instructor.
My further advice would be to focus narrowly. This is always a good idea in academic writing (which I taught for 25 years). The Camino is a very broad topic; an example of a more narrow yet related one would be to examine the daily Pilgrim’s Mass in Santiago where they read the list of pilgrims and swing the botafumiero. That is unquestionably a ritual, conducted by Spanish clergy, and attended by Spanish and international participants, so perhaps that would satisfy the assignment requirements. Good luck! ¡Buena suerte!