Mate, you really, really need to go back to basics and learn WHY you need certain features rather than just relying on asking questions on a forum. Now I really don't mean that to be harsh, I was your age once and I know I've got a heck of a lot more knowledge and experience now. (It's the real benefit of being an old fart)
My advice would be to actually learn by studying the areas you want to move into before you start thinking about any equipment. Use the camera you have for now and test not just it but yourself. See just what you CAN get out of it so it is second nature. Know when you walk into a room what the light level is for shooting in. Guess it and then meter it to see how close you are. it might seem a mad thing to do but understanding light is crucial to good photography no matter what subject.
So make your next investment some good books and take your time.
I had been shooting for 20 years on film before I started to do this seriously and even then I've spent the last three years reading everything I can get my hands on and investing in proper training.
Slow down and get reading.