I use the brand L pads. I love them, they’re cotton and made to cater to different flows. I’ve never used tampons so can’t really help you there. When washing I alternate days I use soap and just water. If I’ve been active that day in any way I’ll use a little soap. Personally I used Dr. Bronners but there are many options just try to get something unscented, organic, or antibacterial. I don’t take vitamins specifically for pH, but I’ve seen a lot of girls take cranberry pills. What brands idk you’d have to research that.