What can i do to maintain my kidney and liver?

Don't abuse them: If you're healthy to start with: well balanced diet, avoid unnecessary drugs (as medicine or for fun), watch alcohol intake; careful with sexual activity/partners- use a condom. Get vaccinated for hepatitis a and b if risk factors- travel to endemic area, sex exposure, especially if multiple partners. If already have some issue with liver or kidney, talk to md about your specifics.