I moved from London to Munich with young children, and know several other people who did the same.
I don't live there any more, though I had a happy time for the few years I was there. I still live in Germany, and there are things I miss now about the lifestyle in Munich (though also things I don't miss!)
I had a friend with a "home help" in Munich, but they were paid for through health insurance because my friend was ill - there is also a service that offers childcare when a parent is ill, and I'm not sure if it was the same thing. I know the home help did various things like cleaning, shopping, looking after the DC a little. Presumably you could hire one privately without being ill, but I'm afraid I don't know what it is called.
The no-shopping on Sunday thing is a bit of a pain. But it is easy to live somewhere within a stone's throw of a small supermarket, greengrocer, bakery etc - they are everywhere. I used to just buy a few things daily rather than do a big shop. You get into the habit quite quickly and lots of the shops are so small it really takes hardly any time. My DC love(d) coming shopping, because they often get given treats - a lollipop, or a piece of sausage, or a banana or a bit of roll, in practically every shop. I was very shocked at first how often strangers (not just shop owners, but people in the street) gave my children things like sweets, or hazelnuts.
Strangers also don't hold back if they think your parenting is not up to scratch - they'll march up and berate you for not putting your child in a hat, or not zipping up their coat or something. They'll often strike up a conversation with the DC on public transport - it's not like London where everyone avoids eye contact.
The Facebook group "Parents in Munich" is a good resource of English-speaking information and support - you can easily become part of the expat community (if that's what you want) and there is lots of advice, and organised or casual events etc.
While I was in Munich, I did find I socialised mainly with other expats, and didn't really integrate that well. Now we have moved somewhere smaller I have more German friends, and feel a bit more integrated. But it was my fault for not trying harder to integrate. There are so many English speakers in Munich that it's easy to fall into just socialising with that group in your own little bubble. Not that there's anything wrong with that, I hasten to add, if that's what you want!