If you want some relaxed shopping, head out past the Museum Quarter, to PC Hoofstraat and surrounding roads. It's much less touristy, with a good range of shops.
Vondelpark is a large park and very actively used at the weekends. It's pleasant to walk through whether busy or not. In general I find walking the canals on a sunday morning is a joy, with the bustle replaced with calm serenity.
Whilst it's not a great market IMO, the Albert Cuypstraat market is still a decent experience, with some enough good stalls to hold interest.
The 9 streets house some great little shops and there is a pleasant vibe about these roads (runstraat, herenstraat etc.). You'll find classy, bohemian and specialist shops here, none more specialist that the toothbrush shop! On Runstraat is the wonderful cheese shop Kaaskamer, with an international range (including smoked mozzarella - the wet stuff, not scamorza) last time I went, but also some fine local cheeses. Whilst in the city, try (and buy if ok to take home) some of the wonderful local mustard and dill sauce. Other countries do it, but we've always been very impressed by what we've tasted here.
In terms of bars, shops & restaurants, don't ignore the suburbs and visiting them gives a different (and generally more relaxed) experience e.g. one place many years ago that had a fine selection of Dutch and Belgian beers, decent food and a lively but convivial atmosphere.
If you've not been on previous trips, I would recommend an early-mid evening walk around the red light district, when it's relaxed, popular and convivial, so you can think about this different approach to other countries, but even then, keep money / valuables safely tucked away from pickpockets. It's not somewhere I'd return to, but I liked the way it made me think about whether open and regulated, or hidden and unregulated is the right approach.
Finally food. It's been so long that any recommendations would risk being out of date. Hence general comments.
- Loads of different cuisines available. This can be good and bad. We had a lamentable meal in an Italian restaurant, but have had other good meals in Portuguese, South African etc. restaurants as well as a better Italian out in the suburbs (Lairessestraat from memory)
- In particular we've really enjoyed eating at an Ethiopian restaurant off Overtoom that I lost the address of, but we retraced our steps through memory. I *think* this is it:
https://www.lalibela.nl/ with the wonderfully fluffy pancakey flatbreads and very flavoursome food. Very relaxed and friendly as well. Note though that the menu looks different, but it's been plenty of years since we've been, so understandable.
- Whether unlucky or not, the Indonesian food hasn't excited me in Amsterdam, though some may argue Ristaffel is Amsterdam's cuisine!