Playing Around With Photoshop

Tried playing around with CS2 today and made some social media buttons. I've never used photo editing software before so I'm really just winging it at this point! The button colors look a little off to me, and the Instagram badge looks slightly smaller. Or maybe I'm just looking too hard/tired at staring at the computer screen. If anyone has any tips they'd like to share, feel free to drop 'em in the comments!