I need help with learing French

Ok so I'm a student and I study french in my school, there's 7 days left till the start of the school and I really need help with grammar, in these years my class had problems with french, we had substitute teachers, then french class was at the last period last year (last period is usually 45 minutes long, adding that we still spend some time waiting for the teacher to arrive we barely did 20 minutes of lesson) then we also had huge problems with the class that I'm not gonna explain. I'm just gonna say that I really need help with French grammar because I wasn't able to learn it, now I do have some basics but I'm pretty sure it's not enough since I also have an exam this year. Please if someone can help tell me 🙏