Don't know how keen I am to help someone with an avi like this...
Maybe if it said "I love my Beer" you'd get more help!
Anyway, It's really great that your enjoying the place and wanting to improve your PS skills. You WILL learn heaps here simply by participating, listening to advice, studying other chops and the feedback they receive.
Basics are really important. Being able to cut/paste with neat edges, colour match and adjust lighting and shadows. The idea is for it NOT to look like it's been cut from another picture.
I've just had a look at your golfer chop and it's really quite good. But a couple of little points you might like to consider. I did a very quick and dirty touch up as you'll see in the ani below.
First I just adjusted the colour/lighting a little as I thought it seemed a little green.
This might be overemphasised a bit, but if you look at 1, his boots probably needed a bit of shadow on the lower part also to 'ground' him a bit better. So when cutting/pasting, look at both the object AND where it is sitting when applying shadow.
Cut objects often bring a bit of their original background colour with them too. If you look at 2, you'll see a greenish tinged edge, because he was cut from a green background. Sometimes you need to adjust the saturation on these because they can stand out awfully depending on the new background colour.
Try to avoid unnatural sharp cut edges like 3.
Lastly, have a good look at the lighting on the new background. If you look at the shadows in the bunkers on the left, it appears the light is coming from the right at sort of 2 o'clockish. Now look at the golfer, and he appears to be lit from the left. So it may have been better to either flip him or the background so as not to get a mismatch.
It may well be worth your grabbing 'advantage' for a three month period to try it out. It's always easier working on higher res source images....and there's usually someone in the 'advantage chat' room to ask if you need advice.
Anyway, enough blabbing from me. Hope this helps a little.