So primary resources is not my speciality, but my kids are all in primary school and I can tell you what we've found useful. For 'structure', ie places that give a topic by topic breakdown of the typical things 7-11 year olds are learning in maths, I'd recommend:

piacademy (no need to subscribe - particularly the 11+ topic wise breakdown. very useful for structure - and challenging too)

oaknationalacademy. This should be great for structure too

https://www.thenational.academy/teachers/curriculum/maths-primary/units

I think its free for homeschoolers as well. But it should give you a good idea of what they'll be tackling at school in each year.

But for actually generating enthusiasm, I'd recommend the nrich website. For example: https://nrich.maths.org/problems/escape-castle

Or, for problem solving (vital skill!), maybe the primary maths challenge website. https://www.primarymathschallenge.org.uk/

Hope that helps!

All the best