Please help me (1031 exchange)

[Maria Felix]

BP family -

Hope everyone is doing well. I'm completely confused please help me understand this 1031 exchange.

I have a cash buyer that wants to buy one of my rentals property for 234K that I purchased 10 years ago for 54K. We signed the contract and looking to close on the 7th of July. Now, my questions are:

1-Do I need 1031 exchange to avoid paying the capital gain tax given that I own the property for more than 10yrs? If so, is this before the closing or after?

2- do I let the buyer know now this is a 1031 exchange?

3- where do I begin? Who do I contact? I live in NYC and the property is in Florida.

4- can I use that profits to invest in more than one property?

Any insight that anyone can provide will be extremely appreciated.

Please excuse my grammar English is my second language.