Thanks for your reply
Closing occurs after the mortgage company is satisfied that the property is really worth what you're paying for it, and also that you can reasonably make the monthly payments. They also want to be sure that there is a free and clear title to the property. These things take some time. It can be a difficult experience, especially if you've never done it before.
The mortgage company should tell you in advance how much money you need at closing. There will be some expenses. Sometimes most of these expenses are "rolled in" to the loan, sometimes not. All that should be planned ahead.
Good luck with your new home.