The best way to ensure your jewelry stays true to the patina it came with is to wear it! Over time the patina will develop a beautiful well loved finish. The shine will take on a lovely glow, and if there is a darkened patina on your piece, it will deepen over time.
To keep your jewelry looking like it did when it arrived to you, I would keep it stored in a container, like the cloth bag it came in or a jewelry box. If and when you think it needs any cleaning, I recommend not using silver polish or a polishing cloth, this usually ends up taking off too much of the patina. I recommend using a Q-tip with a tiny amount of toothpaste, rub it sparingly all over the surface of the silver and then rinse with water and dry thoroughly. A little drop of dish soap and a toothbrush is also a great way to clean your jewelry.
The general rule is that it's best not to wear your jewelry in the ocean, pool, or shower. Salt water, chlorine, and water and soap in general can damage the patina and the metal over time. Best to avoid contact with lotions and oils, as they can especially affect stones.