I’d like to echo what stevewhyte above says, plus a recommendation for primary. Obviously each to their own, but it’s great to have a class of enthusiastic children ready to learn and have fun learning – seems to rarer to have this at secondary level.
I’d recommend contacting local primary and secondary schools and asking to go in and help out, if you’re serious about retraining you’ll need as much of this type of experience as possible – ideally you’d be able to work unpaid as a teaching assistant for a term… (yeah, I know…)