Will I pass 7th grade with a 3.1 GPA
If you study hard and pass all your exams, then you will be able to pass 7th grade with a 3.1 GPA. That means that it will be easier for you to move on to 8th grade and maybe get an even better GPA.
I don't know. How hard and how much time are you willing to put into studying and doing homework. Are you willing to write down notes from your class(es)? and study them?