I recommend you start working with dishes similar to ones you love the best OR that the people you feed love the best. Nothing encourages a cook more than having their food truly appreciated. If you fix something and people at the table just pick at it, or worse yet, say "yuck", not because you didn't do a great job of it, but because it is simply something they don't like no matter how perfect a job you did of it, you'll get discouraged very quickly. Then venture off into experiments with similar ingredients, but different dishes. I firmly believe in avoiding trying to duplicate a dish that someone's mom or a restaurant makes. It is setting yourself up for failure. It can be a fine balance. In other words, if no one you know likes ginger, don't start with a dish heavy in ginger. On the other hand, don't try to make authentic Thai cuisine for a friend whose mom is Thai unless she offers to teach it to you! Ditto a spouse's parent. If MIL makes a perfect _____, don't try to out do her, don't even make it at all unless she teaches you. It makes for good bonding moments and better relationships.
I think developing a specialty is just that ... something you develop over time. You do this after you've developed a few dishes, and you know which are hits and misses. You need to develop, too, a hard shell sometimes. Luckily I've always cooked in an environment where most people like to experiment in eating, so it's easy. When I first moved to the Midwest, I wondered, but eventually I wound up with several "specialties" that were not my specialties at all in younger days.