While power analysis is useful (it is after all what gives you speed), at this early stage reviewing and learning from the race is more important.
Look at it this way: you can be the strongest rider but not win due to poor tactical decisions.
You don't mention the kind of race, so tactical advice can be misdirected ...
were there surges, and did you stay with them?
did you do a turn at the front, and how did that work out?
were you blown off the back?
was there a sprint finish, and were you in it?
were you beaten for speed, or endurance, and how do you think they are connected?
was there a point where people were consistently passing you, and why was that?
was there a time when you seemed to be in the wrong gear, or felt that you'd topped out?
Do work on your power output, and on understanding and extending what you can produce and for how far. But learning racecraft so that you know when to push is equally important.
Also, check out posts by Rider_X on racing.