Internet connection problem

New Mac user at Panera this morning. The Mac Air found the Panera network. All four of the "Wi-Fi" curved bands were dark, and clicking on the symbol showed the network box with Panera checkmarked abd connected. However launcing a Safari page failed, with the little circle indicator twirling away until a box popped up with "server error". There was a Mac user nerby connected to the net and working on-line; she had no suggestions for my problem. I didn't realize there was a network diagnosis function that might have helped. Thought I'd check with the community for suggestions before I went back to

panera or a Starbucks to try getting connected again.