Selling a property and confused with capital gains

[Raza Rizvi]

Hello fellow investors. 

I had a question. I am selling an investment property and wanted to understand capital gains correctly. When I purchased the property I put down 25% downpayment of my own money + closing costs. 

Then came closing costs for the sale of the same property along with realtor commission. 

Question is will I pay capital gains on it all or just what is left after all the deductions mentioned above? 

Also wondering what to do with the money - 1031 exchange or take advantage of the new tax law with opportunity zones.