I’m a current K12 CAVA student, though I only had one year of it + this semester.
I don’t believe attending K12 will jeopardize your chances of a school you’re applying to. It’s an unusual circumstance, but if you’re taking the toughest classes available in your VA and doing extracirriculars outside of school, admissions might see you equally to other students. I myself am applying to UCLA, UCI, Cal Poly Pomona, MIT, CSULB (accepted!).
Ddavviidd’s post is only partially true. K12 doesn’t have science or arts courses that fulfill some of the A-G requirements. I just made a thread about how that screwed me up: http://talk.collegeconfidential.com/university-california-los-angeles/1740740-fulfilling-the-f-requirement-urgently-need-advice.html?new=1
I’m assuming that you’re a junior or lower. You’ll have to take some college courses to fulfill your D and F requirements properly, and I suggest you do that now (if possible) or during the summer. Alternatively you can pass the AP science and art history exams and that will fulfill both high school and college credits for those requirements. There’s an official document for them if you ask your counselor.
Good luck to you! Don’t make the same mistakes I did and wait this long to finish my art credits…