You may get lucky here, but don't count on it. If you're a poet, in particular, you may want to skip this section.
There's not much money in a first book, unless of course something extraordinary happens, which everyone hopes for. Contest or prize money is sometimes part of the deal, though even this money may be viewed as an "advance."
Monies you may receive as an "advance" are more carefully described as constituting what are called "advances against sales." That means you won't seen any kind of royalty until your book sales have paid off the advance amount. If, however, your sales do not make enough profit to match the advance, that money is still yours to keep without obligation. This is a risk the publisher takes.
The most likely figures here are, for fiction, something in the $0 to $5,000 range, with $1,000 or $2,000 being quite common. In poetry, a range closer to $0 to $2,000 is reasonable, with $500 or $1,000 being common enough.
Normally you will receive ½ of this amount upon signing your contract, and ½ as soon as the book is actually published.
Remember also that you may still see actual revenue through sales royalties beyond the amount needed to pay off your advance. But don't hold your breath. Keep your hopes up, but keep breathing.
Also remember that, if you are working with an agent, at least 15% of your payment will be paid to this person or agency.
DVICE. Don't immediately despair about the money. As a writer, you will make money in many different ways. I have always said something about this that has made an enduring, if quirky, sense: I don't get paid for my writing--I get paid because I write.