Originally Posted by Poseidon
Can you even take the ACT/SAT as a sophomore..? I would also look up your intended college's automatic acceptance scores, if they have them and aim to get that or higher on your SAT/ACT.
Yes you can take the ACT as early as you want. Heck I even took it in 6th grade as part of the honors program I was in and scored high enough to get into most colleges around here
I think it's good to go ahead and take it early. That way if you don't score as well as you'd like you have plenty of time to study up and try again. Also check your chosen college's requirements. The ACT has a written portion that was optional when I took it, but that's been a good 6-7 years ago so it might have changed. But some colleges require it and some don't.