Well it's quite simple. :P
I wouldn't necessarily say it's looking bad because it doesn't. But imo there's a few things you could have maybe done a bit better. I'll point them out to you. ^^
1. - That logo you used in there, especially on the avatar. It has those kinda white pixelated outlines. That makes it look a little odd for me. If the logo was bigger before and you made it smaller, there's a way to erase them. Now, assuming the logo was bigger and still had those outlines at the begining. What I often use is go to the layer effects and apply a 1px stroke. Set the opacity to 0% and set the stroke itself to inline. It'll look smaller but the white outlines should be entirely gone. Or try and erase or color them out by hand, that means more work but it will likely have a better outcome.
Of course, if this wasn't a serious project and just for fun this might sound like too much work. But such little details stand out, to me at least! What you could have done too, would be to cut out the different parts of the logo:
Red upper part -> set color overlay red
Blue bottom part with the cup -> set color overlay blue
Result would be that the white pixelated outlines are gone.
I know this all sounds tedious and complicated. There are probably logos that don't even have those outlines to begin with. So use quality resources if you can find them. Dont use whatever you see first, use whatever looks best!
Proper preparation before a project is most of the job already done.
2. - Simple, lame and boring RGB color. A simple and plain blue background. While this might not look totally off, it's kinda boring. It's just MY opinion. Because I like rather complicated stuff. I'm not saying it looks bad, just that I maybe would've add a little gradient in there, or maybe a texture that is set to low opacity. Just a little something that will have it look more fancy to eye. :P This isn't really a point for criticsm, it's just my personal preferance so dont get it wrong!
It's good, don't let things discourage you. Keep going and keep sharing :)