Hello,
Well I am in 9th grade, my freshman year, and I am already stressing about my future.
I have many extracurricular activities…
-Red Cross
-HOSA
-Soccer
-Marching Band
However, my grades are horrible due to my backpack being stolen earlier this year…
I had many projects and heavily-weighed assignments due that week and because they were taken, my grades dropped.
The teachers were less then understanding, and only let me make my grades up partially… In all my classes.
Going into finals week I have,
A+ P.E.
B Honors Algebra 2
B Biology
B Honors Global Studies
B Honors English
B Spanish 2
A+ Symphonic Band
Will this heavily impact my chances into good schools? (Some Ivy League, Private Colleges, and U.C.'s)
If so how screwed am I?
I plan on going for those 4.0’s and higher in the next 3 1/2 years…
Right now, it doesn’t look so good, so you really have to get those grades up to be ivy level
All you can do is do your best work, learn from your mistakes. It does not bode well to be fretting and stressing over such goals and posting on this site to obsess over such things as a freshman. This is not the sign of a scholar. Make it your goal to be a scholar, a thinker and a doer. Do what you can and push yourself to achieve for the learning itself, then assess yourself and see what is a good place for you to be that will achieve your goals. The college is not the goal and I don’t think freshmen should ever be naming the college they wish to go to. Seriously this was never discussed in my household until Jr year.
If you really want to get into an Ivy school, your grades should always be impressive. If that’s what you get before, then what you need to do is excel on the next few years 
You can do it!
Most UCs look at your UC GPA which is your sophomore and junior year grades. Don’t be stressed. Also you should turn your challenges into triumphs; do better in 10th and 11th grade, and you’ll really impress them. They like to see an upward trend in your grades.
There are lots of excellent schools that will be happy to have a student who had an okay 9th grade, but stellar 10th and 11th grades, with good recommendations and test scores. So there is no reason to stress at this point.
One other observation though: "many extracurricular activities’ is not a plus. If anything, spreading yourself too thin is a minus. It means you aren’t putting the time into either your academics or the activities you are most committed to. That’s not to say you shouldn’t dabble - one of the points of ECs is to try lots of stuff in high school and figure out what you like. But once you do, you need focus. There are no prizes for kids who thought their ECs were going to make up for a less good academic performance or that their breadth of ECs could replace depth in two or at most three.
UC’s won’t care at all about freshman year grades. A friend of mine had 3 C’s freshman year and is going to Cal. Your chances for ivies and top privates look pretty slim at this point- but keep doing your best for the UCs.