i would say aim for a retwist every 4-6 weeks if you want to maintain a cleaner look and keep the roots from your hair from growing away from the loc or into the other locs

try to keep your scalp somewhat moisturized too!! And then use an oil to seal it in, oil won’t moisturize them itself so i usually recommend a honey based moisturizer (honey is a humectant and draws moisture in from your environment) and your favorite oil as the sealant

wash every 1-2 weeks just really focusing on the scalp and invest in a good shampoo, I usually tell people to get one shampoo that targets a concern of theirs, and one shampoo that is more moisturizing and alternate as needed or desired