Can I graduate after my Junior year & go directly to college?

In order to graduate early, you must earn a minimum number of credits and have all the courses required to apply to colleges (for good colleges, that's 4 years of math, science, and English, 3 years of history and languages). You'll need to talk to your guidance counselor about whether or not it's an option for you. The other thing you could do is take courses at a nearby college through dual-enrollment while in high school if you can't finish the necessary credits in a single year.