First of all, I always like newbies like you and me because I'm not an expert, I'm a newbie like you and I always know how we want solutions quickly in the beginning so it's not a big deal, don't worry
Regarding your problem, I really can't tell what might be the problem unless I see a screenshot, because I have never had nor heard of such a problem, maybe one of our experts can help in here! but I have to see the screenshot. I will try to help you out with it if you like. (I'm sure you do

)
Saving your screenshot:
by default, all saved screenshots are in your home directory, for example, if your username is Sindibad, then your home directory is
/home/Sindibad/
Accordingly, if you save the picture, I think it will be named by default "snapshot1.png" or something similar, so look for that name into your home directory.
Please let me know if you are still having a problem with snapshooting