How do i use selected items?

[SmokedMemes]

I'm confused as to whether i can use selected items or not, i heard from someone that it was the F5 key but that isn't working so i'm a bit confused because i tried every button and none of them work.

If anyone can shed light on this situation please do. :3


(Also on a side note, i heard you can move downloaded music that's on your browser into your pokepod. if anyone can tell me how i would love that.)