I would do a Tafe course first, check out your local one and see if they do off campus. I know my local one does some courses that way. It will give you a taste of the type of study you would be up for. Just check if any of it can be credited towards a degree if you decide to go down that path. These days for bookkeeping I think they like you to have a Cert 3 or 4.

As for being able to do it with your current commitments, well that is up to you, how much you want it and your time management etc.

Tell us how you go with it