now our comany will subscribe the contract for a web application and website system with another company.

as a user, what aspects should we consider before we accept the software system?

as I am a client presentation, I have the following question to solve, who can tell me what i should do? the contract (or the contract attachment), how many and what kind of test documents should be listed? (besides the test cases and test result of the system test, unit test result)

2.I think the web site application should be do the load test, but i think i should define some criterias to check if the system can pass. but how can i define thess criterias? should i put them into the contract?

3. in general, how many days can I use to check the software if it accord with the software requirement and accepted it so that not only it doesn't delay the process but also it is enough for me to do the UAT?

who has these experience?

It is very important for me.
Or who can tell me where I can find these information about it metion in above?

thanks a lot!