Normally Mikrotik routers factory pre-configured with IP address 192.168.88.1/24 on ether1 port. Default username is admin with empty password.
We suggest to change to your own user name & complex password to protect from anonymous.
Please do login with default username &password .
Please navigate to System>Users
Edit the admin user name with your desired name.
Right below you click on the Password TAB to change the password , leave the old Password area blank Confirm your New Password and Change.
Please restart the winbox and try the new password to gain access.