What class did you fail? B+ and C+ is not failing. And is the geometry class part of your 8th grade report card? If so, it should have little to no effect on admissions anywhere.
Going into 9th grade, don’t overly focus on any one particular college, especially not a hard to gain admission college. Sign up for a challenging course load that you can handle, work hard, develop interests beyond the classroom and keep your college options open. Look at different types of colleges and programs and by late junior year you should be able to develop a list of places that you would be happy to attend. Make sure they are affordable and have some (at least one or two) that you know for sure you can get admitted to.
As for your specific question, I doubt that geometry grade would prevent acceptance. If you continue to struggle with math/science finals it’s possible that it could make it harder to be accepted to highly selective schools, especially if you are applying to an engineering or other STEM major. However, most people feel geometry is very different than the rest of math, so that may not even be an issue.
Don’t forget: Make sure to find a couple of easier admit, affordable colleges you like!