How to study well English grammar?
My advice is to learn English grammar through books. You should read children's books and English books. If not, then you should buy bilingual funny books to read both entertainment and remember the grammar structure used inside. From there, learn, take notes to apply when needed.
And, what is your advice?
Yes I agree with you second option, if you read a bilingual funny book then your interest will build up, never will get bored, And also soon you will learn