Wallpaper and MP3 problem?

Hello guys.

I bought this phone a few days ago.
Two problems.
1. When i post any wallpaper on home screen, never show in full size, only part of him. All wallpaper i use are 1080x1920 resolution.
2. I have downloaded few song in MP3 format, but phone can't "see" them, and i can't use as a ringtone. Need to move in a specific folder or...?

Thanks in advance. :D