For each event, you can add event organisers, contacts / speakers.

If that user has a Preferred Contact Method setup, a link to that will be added on the Event Page (we recommend using Preferred Contact Method of "System" which will keep the persons email address or phone number private). This will only show for certain website security levels (e.g. Level 2 and 3) - Level 1 will require users to login to see these contacts.