church
Another answer: Parochial
Another word for an institution for learning is a school.
Reform School
The word 'religious' is NOT a noun. The word 'religious' is an adjective, a word used to describe a noun (a religious community, a religious ceremony, etc.)The word 'religious' is the adjective form of the noun religion, a singular, common, abstractnoun; a word for system of faith and worship; a word for a type of belief systems; a word for a concept.
wise men.
A "school of fish" is an example of a collective noun.
Dynamic.
Didaskaleinophobia
"Madrasa" is the Arabic word for school. In non-Arab countries, the word is sometimes used to describe a school where Islamic studies are taught.
I assume the learning institution, in which case it is "escola", if you instead meant a group of fish it is "cardume".
learning
Agnostic? I'd say 'non-religious'.
Most texts would capitalize Sunday and School but not the word teacher. Traditionally, Sunday School has been capitalized because it is regarded as a title of an institution.