Internal & External Port Numbers to Reset Way..

I would like to know:

1) How to know which Ports Are being used for a particular web page when trying to send Data..

2) What are the Internal & external Ports that were used for a particular web page..

3) And the Most Important thing, How to reset the Ports as New, so that it looks like to the Access Page that the following Port is New and not Used before…
SEMrush

4) I am Uploading a screenshot off the Netstat, and it shows Port 443 and another Port 59873 (as in the highlighted Below Image).. Now which Port is Used by the Browser Webopage to retrieve results.. How can I know It..?

(​IMG)

Can someone Please explain and answer all my 4-5 Points..?