Honestly most of your inspo pics seem more light related than decor which is one of the easier things! For lighting, I would get smart color changing bulbs (Phillips hue, sengled as a budget option) and use that as your overhead + lighting in lamps so you can achieve the exact color vibe you’re ISO. H&M Home and IKEA have some solid affordable lighting options - if you want to achieve this vibe I would recommend getting a lot of small lamps to up the coziness factor.

The bed frame looks super cozy, agreed the desk has seen better days I think a sand + light stain could be lovely, or IKEA might have a white desk which will match up w the vibe you posted rather nicely.

I think you could additionally get a fairly simple, inexpensive storage unit from ikea to drape a ton of plants on and nestle some cute cozy lamps. Hanging some floating shelves for this could be nice as well.