What do I tell friends and family to do at a Tri event?

Doing my first olympic in April. A couple people in my list of friends and family have shown interest in watching my race. Given that the race is like 3 to 4 hours average.....well what should I have them do? Are there specific points in the race where they can watch me, and then other times where they can like go grab a bite to eat? I dunno what to tell them to plan for since I've yet to participate in it. Can anyone with experience point me in the right direction? Thanks.