firstly i'd like to point out that Kioskea is a forum built on volunteers offering their free time and expertise to individuals who're needing help.
Therefore, it is common courtesy to show respect towards it's members when asking for help. I ask that in future you start and end your threads with salutations.
On your Macbook open up the spotlight search and type system preferences.
From there select Network
in there select the Wi-Fi connection and then advanced.
click the TCP/IP tab and ensure that the drop down box it set to Using DHCP
I would then go into the DNS tab and remove all entries you have in there.
go back to the TCP/IP tab and press "Renew DHCP lease" or disconnect from the network and join it again.