I had loads of experience with kids. And I mean loads. Plus we already had a child.
Initially, my dh thought he had very little experience, except our own child of course, who was 7 at the time - and aside from limited experience with our nephews.
However, for years he had helped at a club that did include a really small amount of much older kids. We were honest about it all, willing to get more experience if necessary but not massively keen to.
My dh had also helped at church with children's groups but it was all quite a while ago. To be fair this was pre Covid and I think they were stricter.
But basically it was fine and neither of us had to get more.
Some places may have stuff on line with kids and you may find just being willing to offer to help as a volunteer is enough.
Personally, I would not start anything without first checking with social workers that it is what they want. You'll need to be honest with the activity and get the whole checks in place etc.
I think we were told initially our own child/nephews didn 't count (basically) they wanted to see how we coped with other people's kids!
But then it turned out out it was ok and neither of us had to do more.
Good luck