Moved, as you wished.
The first is slightly out of focus, and the lighting is - excuse the word - horrible (to my mind, never forget that all the "critique" we offer is very, very subjective!). I don't know what flash you used and where it was, but it sure doesn't do your chameleon any justice.
The second shows a pretty plant, but it is underexposed (looks like that could be remedied in post-processing) and fairly centrally composed (subject in the middle of your photo).
The guitar photo isn't too bad, though I feel there's too much foreground, and all in all it is the kind of photo every beginner takes when they detect shallow DOF (and have a guitar - the others make use of walls or fences or park benches for this).
Even to me, the forum's resident LOVER of the colour green in nature, the third is still boring, lacking in subject, and apparently taken with the camera in AUTO mode, with the flash firing against the near shadowy areas. Says "snapshot" to me...
The sky is too dark. Some post processing can do wonders here, I am sure. But I also feel you have too little "anchor" for that sky at the bottom, just a bit more land would have been better.
I like the waterfall best of all!
But that, too, could do with some brightening (maybe only upping the contrasts some?) in post.