Do I need to call for permission or reserve to take my quince pictures at the park where there's a big water fountain, flowers, palm trees, grass, etc.? Or do I just show up on that day ?

Its a public park..not needed And the flower garden is always open

Not at all, I've seen many people take wedding photos, family photos etc. Just go and do it. It's a beautiful setting.

I think it's ok to take pictures but I'm not a city official to tell you otherwise

I am pretty sure you can just show up but just in case i would call to make sure