All that matters is how you think you did and what you wanted to shoot prior to going out. Set your own goals and strive for them. Congrats on your first shoot. Remember to make them enjoyable.

On 30 targets, I wouldn't personally be satisfied with less than 300 if all targets had 12's but that's just me. If you set your goal for 280's, strive for it and when you reach that goal, strive for more but keep it fun....and if you not in for the competition, keep it about hunting. It'll make you a better shot for each hunting situation.