New kitchen? What would you do?

Jeepers_Creepers

I'd assumed the wonky cupboard was an integrated appliance - without realising it would have been upside-down!

Fit a new flooring over the existing if you can.

Ectophile

That corner you showed looks like damp has got in.  Most types of chipboard or fibreboard will puff up if they get wet.  There's no way to fix it, other than by replacing that section.

You may have to see if you can still get matching parts.  Alternatively, if your DIY skills are good enough, it might be possible to peel off the vinyl covering and stick it to a new board.  But that could easily go horribly wrong.

twopenny

I've repaired a damaged door where water got into the base and it swelled. Well, repaired is a little exageration.

I used something to seal it so it didn't get worse, filled the space with a ready mixed all purpose filler (as it was handy and mouldable), sanded it down and used a little paint to touch it up.

It hadn't actually changed the situation but the eye didn't see the problem when the colour blended and there wasn't a gap.

I also used it to recreate damaged archetraving on a door.  Useful stuff when renovating on a budget and it lasted well.

https://www.amazon.co.uk/TETROSYL-LTD-TETDTE068-Tetrion-DTE068/dp/B0046QAAFY/ref=asc_df_B0046QAAFY/?tag=bingshoppinga-21&linkCode=df0&hvadid=&hvpos=&hvnetw=o&hvrand=&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=&hvtargid=pla-4584001420253128&psc=1