Ask yourself one question: "Do I enjoy playing this character?"
If the answer to that is "yes", then keep playing that character! Use who you want, even if they're a little difficult; I'm as much of a noob as you (actually, I'm probably worse), but in P4A I play a character with awful health who can die if you make one mistake (Elizabeth) and one who is very powerful and simple but has many awful matchups (Labrys). It's not easy using them, but I like them a lot, so I stick with them.