Signing a contract with a new client is usually a good thing, but many interpreters approach it with a mixture of fear and confusion. I constantly advise interpreters to review contracts calmly and take the time to think through each section, including the recitals and signature block.
Most interpreters get nervous when they think about negotiating with an agency (language services company). Of course, you want to make as much money as possible, but you are often told a number that seems low. Approaching the discussion is easier with knowledge and planning.