Hi, just finished my first year at the OU and would definitely recommend, especially if you are used to a lot of self study. I do private tutoring alongside my full time studies and have found it quite good, just make sure to plan and balance out your schedule.
I think working at a nursery is a good start, as alot of the people I studied with do, and they were able to refer back to their experience whenever it was necessary in their assignments. And then maybe after a year once you've built up experience like working and interacting with children- you can apply in schools.
With it being online you'll have more freedom to work alongside studies more than students in brick uni, so when applying for jobs, it will definitely come in handy as you'll have more experience in the field than others.
Let me know if you have any questions!