I bought a house in 2016 and closed on Dec. 2. What portion of my closing costs can I claim?

Go to Federal> Deductions and Credits> Your Home to enter mortgage interest, property taxes, private mortgage insurance and loan origination fees (“points”) that you paid in 2016.  You should have a 1098 from your mortgage lender that shows this information.

Your closing costs on your new home are not deductible except for prepaid interest, prepaid property tax or loan origination fees.  There are no deductions for appraisal, inspections, settlement fees. etc.

Your homeowners insurance for fire, hazard, flood, etc. is not deductible for your own home,

where do i out the orgination fees ?

Under the area for points.

What if at closing I paid into an escrow account and the interest, property taxes, etc. were taken out of the escrow?

Payments made from your escrow account in 2016 can be entered on your 2016 tax return.

Amounts may have been reserved for a future payment of taxes and placed in an impound account. The impounded amounts are for future payments of property taxes and insurance from impound. On the escrow statement you should find an entry charging you for the property taxes for the period Dec 2 to Dec 31, 2016. That amount and the small amount of mortgage interest you were charged for 28 days of interest should be reported to your on a Form 1098 which you receive from the lender. That is deductible on your 2016 tax return. Points paid in escrow should also be reflected on the Form 1098.
Due to the fact that you purchased your new home so late in the year, you may not have enough mortgage interest, property taxes and loan origination fees (points) to take itemized deductions on your 2016 return.