How do we login to WP Admin???

Hello, thank you for your post. I see that you tagged your post as Lightsail related. Assuming you launched your Lightsail with the Bitnami Wordpress stack, you can find the admin credentials via the command line as outlined in the Bitnami documentation[1]. The password is generated automatically on the first boot and it is only available on the system log for the first 24 hours. After you have obtained the password, you can login at http://SERVER-IP/wp-admin. More information on this can be found in the documentation.[2]

References:
[1] https://docs.bitnami.com/aws/faq/get-started/find-credentials/
[2] https://docs.bitnami.com/aws/how-to/get-started-wordpress-aws-marketplace-beginner/#log-in-to-the-wordpress-dashboard