Find out which account has permissions on those folders by doing a "Get Info" on one of them. You might be able to log out from the account you're using and log back in with the account that has those permissions.

Another option: Log in with an admin account. Select a folder with a do not enter symbol. "Get Info" on the folder. Click the padlock icon. Type the admin password. Press the + button and add the account you want and the permissions you want.

There's probably a way to automate all that, and/or to do it once on the main folder and have it apply to all the folders inside it, but I'm not sure offhand what that is.