Caleb has started digital photography as a hobby, and he loves it because it's a non-destructive and positive way to spend his time. Leo says it's a wonderful hobby and with the advent of digital photography and social media, it's gotten even better. Shooters can get better quicker thanks to constructive feedback on the web.
Leo says that there are two kinds of photographers, those who focus on the art and improve their craft with composition, and then gadget hounds that try to get better with technology. Caleb needs to decide what type of photographer he really wants to be.
Having said that, full frame cameras are noticably better for shooting. But there's a very limited selection of full frame lenses. Caleb should pick the system he's going to go with and invest in lenses for that system. So the next step up for Caleb would be to focus on composition until there's enough supporting glass out there to invest in a full frame system.