Create TCP endpoints using T-SQL statements and then grant CONNECT permissions to your login on both principal and mirror servers.

CREATE ENDPOINT [Mirroring]

STATE=STARTED

AS TCP (LISTENER_PORT=1430,LISTENER_IP=ALL)

FOR DATA_MIRRORING (ROLE=PARTNER,AUTHENTICATION=WINDOWS NEGOTIATE,ENCRYPTION=REQUIRED ALGORITHM RC4)

Create endpoint on both servers and then grant permissions and then use wizard.