Standard contingencies written into the contract are obtaining a mortgage commitment by a certain date, and closing on or before the specified closing date.
Other "contingencies" are the 3 day attorney review period (which can be extended, ask your Realtor about the details), the inspection conntingency clause (again ask your Realtor to explain in more detail).
The "standard" contract used by Realtors in NJ has all these things described in detail. Your Realtor and/or attorney can fully explain them to you.
An attorney can, during attorney review, add additional contingencies which would have to be accepted by both parties.