oh so many things to say!!
first: how far do you want to take photography?
if you we're taking these pictures to show friends and family visuals about your trip to greece, these are perfect

if you want to apply basic photography principles, they need a bit of work (although I'm sure your auto mode figured some out)
and if you want to go even further..well..we'll get to that later.
one thing I do want to stress before going too far into the photos is: you want to think about a picture first.
pointing and shooting is good for vacation photos, but while reading your set up, I just felt I had to tell you that you need to have a feeling about your set up when taking a picture. (how many different angles could you have used? what feeling did you want to convey? etc. )
it'll be easier for a person to critique your photo when you have more of a purpose in mind for your photo.
I hope that helped even a bit.
I'm a bit scatterbrained in this explanation, but I'm sure someone else will come along and give you a good critique or helpful advice.
