WHAT GRADE AVERAGE DO YOU NEED TO GET IN A COLLEGE

That is an awesome question!
Depends what is your desired degree.
In general IVY league schools (Harvard, Yale, etc) require very high grades in school an exams.
On the other hand your local community college may have less stringent requirements.
Even many other schools such as art, dancing and acting, among many others rely on your talent and desire to learn.
Last but not least vocational schools have short length degrees with no particular grades requirement.
I suggest you talk to your school counsellor to find your best match.
My nephew chose to forgo all college and took the exam for the US Postal Service, passed it and has been happily working there for many years.
So the options are so many, you should do fine.
Best wishes!