I'm not a networking guy, so I have little knowledge about internet protocols and SSL. My question is coming from a lack of understanding of how https operates.

Basically in https there is a phase where the Encryption algorithm and Private Key to decrypt any encrypted information that may be coming over the network is agreed upon the client and server, however this is all to create a safe and secure connection. But if the Private Key is send before there is a secure connection so what will prevent hackers intercepting this Private Key and thereby also intercepting any https requests that are encrypted but being that this hacker has the private key the data can easily be decrypted, so where is the security?

This always bothered me, thank you for all your answers!