Having the right tools can mean the difference between a quick project and a complete mess. Fortunately, you won't need too much to handle the projects here and what you will need is pretty inexpensive (certainly less expensive than hiring a plumber). You can get everything on this list for about $100, and you won't need it all unless you're doing all the projects. Where I live, that's about the cost of hiring a plumber for an hour.
The word "plumber" dates from the Roman Empire. The Latin for lead is plumbum. Roman roofs used lead in conduits and drain pipes and some were also covered with lead, lead was also used for piping and for making baths. In medieval times anyone who worked with lead was referred to as a plumber as can be seen from an extract of workmen fixing a roof in Westminster Palace and were referred to as plumbers "To Gilbert de Westminster, plumber, working about the roof of the pantry of the little hall, covering it with lead, and about various defects in the roof of the little hall". Thus a person with expertise in working with lead was first known as a Plumbarius which was later shortened to plumber.