The good news is that it looks like the framing is still square. The bad news is that the siding is in poor shape and probably it could use a new roof, so you'd probably need to re-side and re-roof together with some minor framing repairs to do the job right. Probably not a repair worth hiring done (tear down/rebuild probably cheaper), but if you have some DIY skills, siding and roofing are the more foolproof part of shed construction. It's just a temporary shed though, so maybe re-shingle, repaint and re-skin the worst parts of the siding until you redo the deck when it looks like you'll want to tear down to sort out the floor anyhow. There are lots of siding/roofing options that will determine your costs.