I need an email address list created for 500 contacts

I would like you to search for contact email addresses for 500 schools. I have the school website, so I would require you to go onto the website and find a contact email address to input in my spreadsheet.
The next step of the project would be to send personalised email (from a marketing email address that I have set up) to each of the contacts on the list.

See attached, the ones in yellow I have located the email and they have been sent an email already