Within the realm of basic imagery and simple touchup, I'd definitely say that you have some well-grounded skills.
Please keep in mind, however, that the majority of images you would retouch are likely to be extremely high resolution; that being said, your image is decidedly low-res, meaning that when you scale it down all the little imperfections, missed lines, etc. disappear within the resize. This is good and you have a good foundation (and it's not like anybody picked up a tablet one day and became an expert). As a photographer, you'll likely know the trouble areas and where retouch is likely to draw the eye as fake and whatnot.
I say go for it, you have a good start and there's always a lot of help on here!