No idea...

[absolutelynoideas]

I have a large bed in our garden where we've lived for one year and I have no idea what half the stuff is. Not sure if I need to pull up / if they're weeds? Any ideas? What should I do?

More pics

Looks like you've got buttercups, elder or ground elder and a cress and a cow parsley. Possibly some bulbs/tulips/daffodils.
You could dig over the whole lot for a clear space and pop any bulbs you find back in to see if they come up next year.

I would clear the space and sow with a wildflower mix for this year whilst you plan what you want for next, based on soil type, sunny or shady etc.

Everything that isn’t a tall thin strapped leaf is a weed. In the left picture one with white flowers is hairy bitter cress and will spread like wildfire if you don’t get it out before the flowers finish and it sets seed. The thing above it is creeping buttercup and roots spread and another plant pops up, so see if it’s attached to another one when you dig it up.
Photo top right, ferry looking thing is cow parsley. Deep root, dig round it in the centre and try and get it out. Bottom right if it’s ground elder you need to get every bit of root out, it’s a sod to get rid of.

Glad we agree on those, Whatever!

Yes the long thin leaves are flowers you want the rest you probably really want to get rid of (but might not find it easy. Ground Elder is a bastard.

Agree, just to add that ground elder spreads underground with runners that look a bit like spaghetti, they can keep going for ages with little plantlets popping up on the surface all along its length. You need to trace the root/runners back all along the length and try and get every scrap out or it will regrow from the tiniest piece.
So in your position, i would go over the whole bed carefully with a garden fork, not a spade because that would just chop up the roots and redistribute them, and remove all the roots. Then plant annuals for this summer so you can more easily remove any weeds that regrow. Villagetoraiseachild's advice is spot on.