English is the official language in Nigeria, and that is what schools teach in. Of course other languages are taught as well. The tribal language of the state for instance, and French, and possibly others.
In Nigeria, the school year currently runs from January to December, consists of about 3 quarters with a month between quarters.
Some Nigerians go to nursery school in their early years.
For children who do not go to nursery school, the first level of schooling that is attended is Primary School (Primary 1 through 6) equivalent to what is called 'elementary school' in some other countries. This runs for 6 years, and after that, students take the Common Entrance Examination to be admitted into Secondary School, which is the equivalent of 'high school' in some other countries.
Also, for Secondary Schools, boarding schools are a quite common alternative to day schools (non-boarding schools). After Secondary School, students can enter Universities, Polytechnics, Teacher Colleges, Trade Schools, etc. etc.
Of course, a number of students also go further after University/College on to graduate school.
Because college lasts for about 4 years, you'll sometimes hear this education system called the 6-3-3-4 system.
Before a person can start working in Nigeria (of course, if they start their own company, this does not apply) they need to have one year of National Youth Service Corp. (NYSC), and most Nigerians go through this right after school.
During primary school and secondary school (both parts), students wear a school uniform that is chosen and designed by their school. During school parties or special functions, students are sometimes allowed to wear what they choose. Also, there are usually other physical standards that students must abide too. For instance, most schools either have the girls hair cut short, or allow them to braid it neatly, sometimes depending on the grade level. Boys must have their hair short. With both boys and girls who have short hair, the hair must be neatly combed. Also, shoes, jewelry, and other accessories usually have guidelines attached. Boys are usually not allowed to wear jewelry. Neatness is very important, and your school uniform must be clean and ironed, which was sometimes difficult if you had no electric power between the time you washed it, and the time you wore it (unless you were lucky enough to have a generator for power outages). So, many students usually have 2-5 identical school uniforms. Also, because the weather is so hot, you sweat a lot, and wearing something more than a day in a row (between washings) is avoided.
For those going to boarding schools, in addition to the school uniforms that are required, there is usually also a “house uniform” that the students wear after school hours.
There are no restrictions on attire and appearance in higher education.