I'm really new to programming apps - so this question might sound a bit strange: I'm trying to program an app in android studio, where people can upload different things (basically strings and links put together in some kind of "package") and other peoble can then decide what "packages" they want to add inside their app. However after downloading, this data should be stored on their device and not just in the memory of the phone so that they can use it after restarting the app (and also if theres no internet connection). Do you have any idea what would be the best way to store this data both on the phone and in a database and how to synchronize the data on the phone with the selected data from the database. I really dont want to know how to do this exactly but would rather like some basic ideas and maybe you could tell me what kinds of stuff i should learn in order to succeed and what kind of database would be best here (firebase, MYSQL,..)?
Thanks a lot, Andi