1Read the latest news, articles to stay current and entertained.
To avoid feeling bored in a public place, reading is a way to go, especially when there is no one to hangout with. Read particular news articles that interest you, maybe Politics, Technology, Entertainment, Football, etc.
You can equally do some research on materials, softwares that you believe would be of a benefit to your personal workflow, academics, that if pitched to your boss or school instructor would get you ahead of your contemporaries.