Even if its your first time then it wont really be that hard to understand the mechanics of this art competition.It is really just basic and could really be understand on first read up.
Speaking about the competition which there are people who are really making it for passion but cant really be denied nor ignored that we are mainly aiming for the
prize which is really actually that generous if you do ask me.
One of the best things in life is doing what you like to do and getting paid for it. There are a lot of talented people here on this forum who enjoy what they do and if they get a (nice) prize from participating in it, than that is even more better!
Having a mindset like this if you join in any contest is really good because you're not expecting to get something in return but you mainly join because it's your passion and you love what you do. Like what @rozak said, less pressure if it's your hobby and you won't get disappointed if your entry is not chosen. But of course, who don't want to win right? The prize is quite good. If you decided to join it's best to have less expectation so it's not hard to accept the outcome just incase.
How can you create a beautiful art if you are not expecting a return? Your competitiveness will not be sharpen if you are not aiming to win. And you cannot test your skill if you are here create an art then just post, then it will be useless at all if your not aiming anything. So for everyone who plan to participate and want to improve do all what you can do to win the contest since from this you will be more inspired to create competitive art works to win the prize.