Ask HN: Tips for building web-app permissoned access

Hi all, I have an inch of knowledge in front end programming (self taught), and as part of a project, I'm looking to develop 'permissoned access' for a web app I've been building. What I mean by that is allowing users to create accounts and storing the relevant data for those users securely for when they return to view it. Do you have any resources, tips, or advice on where to start in building this? Thanks