Forget and Reconnect
Click the Apple Menu in the top-left corner and select System Settings
Click Wi-Fi in the sidebar.
Scroll down to the bottom and click the Advanced button.
Find your SSID (Wi-Fi name) in the list of "Known Networks.
Click the three dots (...) next to the name and select Remove From Network.
Click the Wi-Fi icon in your top menu bar, select your Wi-Fi, and type the password again to reconnect.
Request a New IP Address
Go to System Settings > Network > Wi-Fi.
Click the Details button next to your active Wi-Fi connection.
In the sidebar, click TCP/IP.
Click the Renew DHCP Lease button. Click OK to confirm.