I want to apply first round to a couple of programs this autumn, but I have no math coursework whatsoever.

My plan is to take Calculus I and Statistics I through SUNY Online, but I'm curious if anyone knows the sort of time commitment needed to wrap your head around these classes. I would hope all the refresh work I've done for the past 4 months in preparation for the GMAT would count as a good primer, but I also have a new job leading a new team on a new project, and I want to know if anyone has had experience doing multiple online math courses in tandem?

Thanks in advance.