Anyone could draw their own manga, but the quality of it depends on how much effort you put into practising and drawing!
Your drawing style seems to be a lot different to mine, so I kinda feel like the pic is stretched/elongated. But that's probably just your style so all is good. ;D
Quick run down of the stuff I noticed:
Umm.. make sure before you draw on the clothes, you at least do an outline of the where the legs will be. That way, when you draw in the feet, you'll get the right size and positioning. Something like my redline... kinda.
This was done really quickly so it's not even close to perfect. And the feet were just drawn in as boxes. D:
[EDIT] I only just noticed after looking at it again, but i've drawn in the feet a bit bigger than I meant to. His left leg is also thicker than I originally intended. X____X Less slopey shoulders; shoulders have definite shapes and don't really drop down that much. Guys usually tend to also have broader shoulders, but that all depends on the build of the character and also your style.

Also, you should work on clothing folds. Study the way that clothing sits etc.
Sorry if I sound a bit harsh/crude, but I'm in a rush, but yes! Your drawings are quite good. Keep drawing and practising and you'll be able to do a good manga. Hope this is of some help!