User authentication and return SharePoint list data to mobile app

Hi Everyone,

I have to achieve below requirement. Please help.

Environment - Office 365

Requirement:

1. User Authentication: From mobile app how can we authenticate user using O365/Azure AD login credentials?

2. Share List data to Mobile App: Once user has been authenticated how can we retrieve SharePoint list data in subsequent request without sending login credentials each time?

Thanks,

Kalpesh