Naturally ph water that is beneficial and not gonna hurt my plants

You can dissolve dolomitic lime or calcitic lime to raise water ph, can also be used to change soil ph. Dolomitic lime releases calcium and magnesium ions when dissolved. Calcitic lime releases calcium ions. Take that into account when feeding other nutrients with calcium or magnesium and adjust accordingly. Phosphoric Acid will lower water ph, can also change soil ph.

hate to tell you, inorganic molecules are "natural" too, lol. a base is a base. an acid is an acid. being organic or not does not impact the function at all. since all bases are H+ donators or acceptors, many will be "organic molecules" - science term not marketing nonsense. While not 100%, most molecules that contain C,H,O,N are organic. There are exceptions, like CO2. CO2 is an inorganic molecules and probably 99..9% of molecules that the plant builds for growth and maintenance depend on it as a source for C. Your plant is always made from inorganic material... always.

Vinegar will work, but if you are growing in soil, the pH of untreated rainwater will not cause any issues anyhow.

You can use lemon juice or vinegar to bring the pH of your water down. Just add a little bit at a time and test it with a pH meter until you get it to the right level. You can also get pH up and down solutions at most gardening stores.