How to build membership app easily?

Hello, I need to build a membership app to host content for B2B e-learning.
Can anyone point me to resources where I can find tutorials on how to build an app of this type using React Native (or Flutter) components, upload the content using some database such as Airtable and deploy the app?
Unfortunately I have no budget to hire a dev so I need to figure out the app building process, also keep in mind that I'm a very noob coder.
Thanks to anyone who can help me!