How do I figure out what my BJJ game is?

Look at your natural proclivities - what you do well that just makes sense to your body. Listen to that and build a game around it. Also look at people who are built like you, both at your gym and at the highest levels of competition. Find someone with similar body type and athletic abilities, then mirror your game off theirs. This usually happens around blue and purple belt when you know enough to start whittling in and finding your style.