If a publisher wants your book, you'll receive a contract. The publisher is hoping, a little bit, that you won't read it.
All contracts are negotiable, but publishers count on writers being too dazzled or timid to ask for what's fair. I can tell you what's negotiable and fair, what's typical, and whether you should consult a lawyer.
Please contact Catherine about a contract review. It might be a very simple matter, or require that you negotiate with the publisher to get you a fair deal. Don't be exploited or sell yourself short. Ask someone experienced.