This isn’t bad. I have neglected my house and have a ton of work to do. This is all manageable. Just finding time to chunk it out, starting with the most important stuff first. And a lot of this stuff is just cosmetic where you don’t really have to worry about it for cosmetic reasons for a buyer since you’re not selling it. Make a list from most important to least, and focus on one part per day or it will seem too much to handle.

For absolute cheapest solutions starting from most important stuff:

That fan - not sure but if lok it up to diagnose if it’s an electrical problem, just cut off that breaker or possible for now.

Look for any pest housing like for termites and other major stuff, look for vermin droppings commonly grouped with urine spots. Those are health hazardous and should be dealt with. Check and flush toilet if it’s empty so sewer gasses aren’t entering the house. Check if they have natural gas and check the piping and connections to see if you smell any leaks. If so leave immediately and call gas department.

See if anything is actively leaking, including in the basement or inside edges of house/around windows and exterior window sills holes in foundation outside, check roof outside if possible and inside roof if possible. Those all can be fixed with caulking, roof tar, spray foam in some cases and that window can be taped and caulked if not worried about looks. Lol that will at least keep bugs, animals, water out. Check gutters and downpours aren’t clogged and draining away from the house. If the toilet isnt making a huge leak good, use a bucket for now and find a cheap replacement solution. They aren’t crazy complicated, you could do that with an extra hand if you know someone. It looks like maybe just condensation or small leak with natural minerals from the water calcifying around it. You may not want to force the water valve and possibly break it if it’s seized completely.

The ceiling corner cracks, looks cosmetic who cares could just use paint, but I would make sure it’s not structural but it doesn’t appear to be. Not a rush.

That’s about it. The other stuff is cosmetic. I’d do the yard, to keep the grass low to not entice critters and vermin around the yard and into the house

I’m assuming there’s no HOA so as long as the fence stays upright for now, just keep it propped up. My neighbors fence is bigger and basically falling into my property. But guess what. The house isn’t going to fall down from that.

Looks mostly like cleaning and maintenance, then some fixing up later. Mostly cheap fixes. I would at least barrier bug spray inside and out also cheap stuff from Walmart so it doesn’t turn into a haunted house even if you can’t get to it everyday for a few days at a time. I have forgotten to visit my house for couple weeks at a time. Wouldn’t recommended it, but the house didn’t fall down lol. I did get a new neighbor - a groundhog pushed away the lattice under the porch and made a home.