I am looking to buy a new laptop, most likely a hp envy. However I do not know what processor to choose...a intel or amd? What is the difference? I will be using this laptop for school, browsing the internet, storing photos/videos/music.
Well for what you are going to use it for it really come's down to the price as an intel or AMD based laptop is going to perform just fine for that. Get the one with a good size hard drive and ampul amount of ram with screen size you want and you should be fine. If you are not going to be gaming on the laptop just get the one that meats what you need.
The main difference is that AMD will give you more bang for your buck. I would choose this one from the page you gave http/www.costco.com/HP-ENVY-dv6z-Laptop-AMD-Quad-Core-A10-4600M-2.3GHz.product.100032538.html
If the OP will be using graphically demanding applications then yes. However, if the OP is not gaming then IB i5>>>>>a10.
(a10 competes with, and generally loses in cpu performance, with a SB i5).