This is the 6323rd most frequent Russian word.
учебный
"Учебный" means "educational" or "related to learning/studies."
Here, "учебный" is used as an adjective to describe "plan," indicating that the plan is related to education or learning.
Мой учебный план включает изучение иностранных языков.
My study plan includes learning foreign languages.
In this sentence, "учебных" is the plural form of the adjective modifying "purposes," indicating that the purposes are related to educational activities.
В учебных целях мы посетили музей естествознания.
For educational purposes, we visited the natural history museum.
Here, "учебный" is used to describe "classroom," highlighting that the classroom is designated for educational or training purposes.