Make sure you network settings are set to use the DHCP server on the network. In your wifi settings, long press the connected network and select Modify network config. Check the Show advanced options box and make sure that IP settings is set to DHCP and Proxy settings is None (May be able to use proxy, but may have to add something to use to bypass list so that you can get redirected to site to accept ToS).
Using my Galaxy S4 (4.2.2) as guide since I don't know the device or Android version you have, basically your steps may vary some.