Willow,
flowering current good for early spring.
Any and all fruit trees and bushes (if it makes fruit it must make a flower first which needs to be pollinated).
Horse chestnut, cherry - bird and wild, sycamore (although everyone hates it it’s actually good for pollinators and makes good firewood and responds well to coppicing.
I observe bees on my oak trees and Scots pines, I think they must be after the sap or something, not sure but they’re there. When in doubt go for diversity.
I’m also planting cotoneaster shrubs and Budleia bushes for pollinators.
Don’t get too hung up on whether it’s for honey bees or bumbles or butterflies or hover flies.
Sounds like you’ll have space to do some more ground/herb later plants: a herb garden - thyme, sage, mints, etc, etc, and anything that is from a cottage garden or weedy old flowers like Mullen, Vipers bugloss, self heal, rather than anything professing to be “better, new, improved” -it isn’t. Extra colour and double flower heads are pretty much useless for bees, most roses, daffodils, etc, are useless to very poor.
If you’ve got a space and in any doubt do clover/vetch/birds foot trefoil/ dead nettles. Archangel is good under trees.