My siblings and I retrospectively have achieved well (My brother had a shaky start academically but is now a well respected barrister with a dodgy CV!).
We were a squeezed middle lower class family with very working class roots. My DM left school at 16 and while her family didn't value education she did. My DF was a graduate and his parents really valued education both for their children and us, the next generation with both money and time.
Money was tight in our household. Very, very, very tight during the 1991 financial disaster. We went on infrequent holidays abroad paid for by grandparents. We always went to historically interesting places e.g somme, normandy beaches. Grandparents also at various points gifted national trust/ english heritage type memberships as presents.
We mostly went to state school. I did 2 years at private school (grandparents again) after a house/ school move made me really miserable and I wasn't being stretched academically.
But... there were a lot of books in our house, we went to the library regularly and were encouraged to borrow and read widely. My DM would organise us for to do loads of stuff in school holidays - museums/ castles/ stately homes often with my paternal aunt who was a teacher.
If we were doing a school project my DM would arrange relevant trips/ get books from the library etc, Other family members would chip in with their areas of expertise e.g language practice. There was always a lot of current affairs chat at meal times and most of the time there were newspapers in the house and we were encouraged to read them. When things were really tight for money we would get the papers second day from my grandparents who got several each day. At various points New Scientist/ National Geographic type subscriptions were given for christmas. We had a computer, printer & scanner to do so school work with when this wasn't that common. I submitted a typed project at the end of primary school - this was extremely unusual at the time.
Sport/ Music etc. was encouraged but constrained by £££. Guiding lent lots of opportunities for me. My DBro got a lot out of air cadets.