In Hogwarts School of Witchcraft and Wizardry almost all students have their own pets like owls, cats, toads, etc. I understand that students need owls for communication, but is it necessary that all the students must have a pet of their own?
The exact wording in the Hogwarts letter is
Note “may”, not “must”. For example, Hermione doesn’t have a pet until the third year.
Most students also won’t have their own owl. The school owlery has a set of owls that anybody can use for post, or there’s the post office in Hogsmeade which is accessible to the older students.