If you had D or F grades in 9th grade, it may become a problem in terms of counting required high school courses for some college admission. For example, if a college requires you to have 4 years of English in high school, but your 9th grade English course ended with a D or F, that could pose a problem unless you take an additional English course, or if the college allows some other means of fulfilling or replacing that year of English.
You can calculate your GPA with the hypothetical of 8 additional A grades added to your previous grades.