Don't know about it being hard or easy, that is all in one's perspective.
I find building an FM transmitter, tower, and studios easy but very time consuming and there is much meticulous work. Others look at the station when I am done and ask, "how in the world did you build all this, you must be a genious?"
No, I just read a lot and attended N.C. T&E, not to be confused with Texas A&M.
N.C. T&E is N.C. Trial and Error.
3DGS is the same, much reading, much time, ideas between other engineers (designers and builders) and a lot of Trial and Error.
As one input said, do not expect to get it down and put out a game in one year. Won't happen, unless you use all the template codes and make a simple 5 level game, spending 12 hours a day making it and not worrying about shaders or lights or texture line-up, all the detail work.
You may be able to do it, you are young and have a lot of "brain" space left.
I'm old, older than the guy that said he was 40. So my brain is not quite as fast at picking up things. Took me years to understand broadcast engineering and I still am far from all the answers.
Deligence, patience, willing to accept errors, and taking advice from the Experts, (of which I am not) will go a long way to your becoming successful.
I can only devote a few hours a week to this, but I enjoy making the levels and the game more than I enjoy playing each level.

God speed and happy gaming.

David Robinson