Xamarin Forms app (Examination with pictures)

My app needs to do

1- Should Support different screen sizes ( How can I do?)

2- Should Support Multi Language ( How can I do?)

3- There will be too many pictures in the app( how can I store ? ) Localdatabase, Cloud or web services (i don't want to use Azure and firebase)

4- How do I show pictures ? ( gridwiev or tableview etc.)

Best regards ...