The issue is 8GB is way too little.
Even if you didn't install any apps. You will still have to be very careful with photos and music and video.
So u can barely take photos. Than what's the point of a smartphone?
The way Apple counts photostream against ur GB of internal storage sucks as well. So u essentially have to delete both internal photos and photostream to free up storage space INTERNALLY on ur own phone. What's the point of photostream than?
Use iCloud Photo Library instead. I do. Works only okay though.