Great pics... good 1st effort
What I have found is that initially after going from a point and shoot to a DSLR , your pictures suffer a bit as the DSLR does not give as "pleasing" results as a P&S on auto does - you got to know a little more about F stops , shutter speeds etc etc.
Plenty online camera tutorials - the first thing to learn is the rule of thirds....
The 50-500 "bigma" lens is not a great lens as it has some "defects" , it is not image stabilised and goes to its 6.3 F stop quite early on in its zoom range (i think its at this at 125mm or less) - with a cropped camera , you need speeds of 1/800th of a sec at 500mm zoom (rule of thumb is that you need shutter speeds of 1 over focal length to combat camera shake), so in reality with this lens , you either need a tripod/monopoid and/or need to use iso's in the 800 range to get acceptable results. I had one of these lenses and sold it ... had issues focussing under lowish light conditions and the high ISO's produced some grain in the pics , also I had a polarising filter for this lens that was unuseable as it didnt allow Autofocus (it reduces the lens to like a F8 or worse as it stops light coming in) ...also had the 1.4x convertor , this too was useless as it didnt allow decent AF - it reduces the light by one stop - a lot of DSLR's wont focus properly with an effective F8 ... it's really a lens you can only use under ideal conditions.
I think you would do better with a 70-200 F4l and a 1.4x convertor if you really need more tele or the Sigma 80-400 stabilised lens..
The 2 lenses I suggest for cropped cameras in the Canon range (budget wise) are the 17-85 IS (can be had 2nd hand for R2500 or so) as a general walk around and then the 55-250 F4-5.6 IS as the telephoto lens (new around R3k , 2nd hand around 2k)
If you really like extreme Wide angle , the Canon 10-22 is a great lens...
