A very basic and simple start to my R2D2 model! tell me when you think so far!
http://www.mediafire.com/download/9mqo1s1h3lfu4y2/r2d2.blend
^ link if anyone wants to take a look at my blend file!
I’d suggest you take a look at your lighting setup. For me the render is so dark it’s impossible to tell what you’ve done. It may be great, so why hide it in the dark.
I just checked out the blend file and it looks as though you’ve applied the majority of your subsurface modifiers. As a general rule of thumb, this is bad as it makes the topology incredibly hard to edit later on. Also it looks as though the scaling of certain parts is off (the shoulders being really noticeable IMO), so I’d suggest grabbing some blueprints off Google Images or wherever and using them as a background image for reference. Keep going, I’m a huge Star Wars fan. 
I’ve tried to make a lighter version for you to have a look at.
I’ll have to call this a final render as I’ve already applied the subdivision modifiers and can no longer do much with the model. Sadly my modeling skills don’t go all that far as I’ve seen so many better models floating around, but i’m relatively happy with this considering :).
I know you say you are not good at modeling, but you can certainly improve. I remember the first couple I tried. It was a mess and I was proud of that mess I made, but I kept at it and now I am much better at it. Save all these early efforts. They are fun to look back on once you have gotten better at blender.