Hi, Linda. Try to take one thing at a time and your water problems are probably the most serious. You might start at a used book store. They usually have multi-volume sets of home improvement books pretty cheap. Being a little out-of-date is not usually a problem.
The next step would be to call a plumber and have him replace the water pressure tank. While he is there, you can ask him to check the other water related items. Your plumbing will determine some of the answers to the other problems. If you don't know a plumber, visit the best independent plumbing contractor in your area and ask them for recommendations.
You can also have the tub and sinks repainted, but this is a pro job too. If they are in good shape, it can save a lot of money.
Bi-fold doors falling is a common problem and I'll bet this is mostly in the kids rooms. Take the doors off, put toy storage in the bottom. If they are still in good shape, reuse the doors to replace problem ones in other parts of the house. Isn't that easy.
This should give you some start and probably others have answers on other parts. Check the board and you will probably find answers to a lot of your other questions.