If you look at the background's the line of the field etc they're a little bit wonky, not miles out but not straight. Not a huge issue just thought I'd try to help by pointing it out.
You are in no way out of your depth here! We're all still learning, I don't have half the equipment that some pro sports photographers have. All the stuff on my site is shot with a 70-200mm lens.
I had a look at your flickr and there's some great shots in there, it just takes a bit of time to get used to things like cropping, composition etc. there are lots of very friendly and helpful people on here, if you stick around and take their advice I have no doubt that your skills will improve a lot quicker!