Making flashcards is a great way to study. :)
What got me through middleschool spanish tbh was probably making lists.
I had a separate journal for studying where I would go home and rewrite the important information there and group it based on category, for example, "Vocabulary-foods" and "Conjugations- stem changing ue verbs"
Hope this helps!
A) 28 - veintiocho
B) 14 - catorce
C) 12 - doce
D) 19 - diecinueve