Where should I start

Hi! First time posting in this sub. I thought I’d come here to see if I could get advice on how I can become an ESL teacher. Currently I am in early childhood education. I do not have a degree, only certification to teach preschool. I’ve always wanted to pursue teaching in a public school setting and I feel really drawn to ESL. I work full time and have 2 young children so when I take classes it will probably only be 1 or 2 per semester and would mostly have to be online. I guess my question is, what classes/degrees should I be looking to pursue if my goal is to eventually become an ESL teacher at an elementary school? And how long does it typically take to become fully qualified?