Connection timed out is generally like a busy signal. It just means the web site reached its maximum number of users, and your computer was unable to communicate with the site. The best thing to do is try again later. 403 - Forbidden appears when you try to access a site that is restricted in some way. It may be a site that requires a subscription, or you may have to go to the site's home page first before you can look at the rest of the site.
Some sites are only available to designated users.
Another problem may be that accessing web pages with large graphics or video files may take several minutes. If your computer freezes up completely and it does not respond at all, the only thing you can do at the library is reset your computer and start over. Ask at a Reference Desk to find out how to do this. E-mail stands for electronic mail. Most of them provide e-mail for free because they are supported by advertisers.