When I first entered 11th grade, I had a schedule conflict between Honors French 3 and band because they were in the same period making it impossible to take both. I decided to take band and take AP Stats instead this year but is taking only 2 years of language bad for competitive universities like Northwestern or Rice? Should I consider taking french 3 next year after a year of break or should I not worry about it? (btw I want to major in engineering or pre-med)
My current schedule:
-Band
-Honors Computer Science
-AP Stats
-AP Physics 1
-APUSH
-AP Lang
-Honors Pre Calc
Next year schedule
-Band
-AP Lit
-AP Gov/Econ
-AP Calc AB
-AP Bio
-AP Physics C
-Honors french 3 or AP Comp Sci
Neither band nor stats would be considered core classes.
Don’t take AP Bio and physics C together. The labs I’ll make your life impossible. Since you want to be an engineer, I’d replace bio with French 3.
Each university puts its admissions requirements, and recommendations that aren’t strictly requirements, right on its website. Likewise, the graduation requirements for your projected major will be right there as well. Is FL required for graduation with your major? Can you get that waived with a certain SAT II or AP score or a certain number of years of HS FL classes?
Read the websites, and find out just exactly what these two institutions require.
Do a little review (Quizlet, Duolingo, French language movies on Netflix/Amazon, LeMonde.fr, etc.) and take French 3. You don’t want to limit your college choices, plus learning a language just makes you a more interesting person. 
NU only requires 2 years FL though most applicants will have more. Also, in order to graduate, NU requires 2 full years of college level foreign language, which is 6 courses (a lot for someone who doesn’t like foreign language). The better your French is by the time you graduate high school, the higher you will be able to place on the FL placement test, and the less classes you’ll have to take in college. (This is similar for many schools; I just happen to know NUs policy).