[Adult Learner/Algebra I] Algebra I to Calculus I ready, can I be ready in 14 months?

I'm trying to better myself, and I'm going back to college next fall for engineering, but we've got one problem with that.

This is a massive shift in majors for me. I graduated in 2014 with an associate's in mass communications, but realized it wasn't what I wanted anymore. Honestly, I wasn't ready for college maturity-wise and I didn't do as well as I had hoped- got a 3.2 but I still feel like I got off too easily.

My biggest obstacle is math. I've always neglected it and it is coming back to haunt me. I have set a goal for myself that I'll be prepared for Calculus I by the fall of 2018, but is it realistic if I start from Algebra I? How should I approach self-teaching? I've got some old textbooks, Khan Academy.. What else?