Masseuse cleaned my anus with her finger covered with wet wipe. finger isn't fully inserted but maybe partial(since she said it's to "clean"). is there any chance of catching std?

If this was the sum total of your interaction with the masseuse, there is no risk to your health. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-preventio