The solar system is swimming in water. Europa alone is thought to have 3X the amount of water in the Earth's oceans, and it is only one moon in the Jovian system (Ganymede and Callisto are ice moons even bigger than Europa, and Jupiter has at least 67 other bodies of various composition in orbit).
If that is not enough, Saturn's rings are thought to be made of small chunks of ice, and may Saturnian moons are also icy bodies. Uranus and Neptune not only have flotillas of icy moons in orbit, they themselves are considered to be "ice giants" rather than "gas giants".
Going farther out, the distant bodies of the Kuiper belt and Oort cloud are all considered to be made of ices of various sorts. Asteroids are also known to have water trapped or embedded in them, and they alone have something like 4% of the mass of the Earth, while the Oort cloud is estimated to have anywhere from 5 to 300 time the mass of the Earth (the estimates are very wide due to the lack of direct observation of the cloud).
So water, in the form of ice, is very common and abundant in the Solar System. Getting it requires enough deltaV to leave Earth orbit and match orbits with the body of interest, but some Near Earth Objects (NEOs) require less deltaV than needed to get to the Moon, so you can start small and work your way outwards. Once you get to the ice, you will certainly need enough energy to melt it, and most likely some process to remove trapped gasses and filter out impurities like bits of rock, salts and carbon that may have been trapped in the ice, but after that, fill your glass and enjoy!