Thanks for the info, it means that the instance is a bit old. We recommend you to update edX to its latest version once you get access to the machine. We also recommend you to do a server backup so you can start from a known state in case anything fails.
You can find more information about how to do a server backup by using our guide at https://docs.bitnami.com/aws/faq/administration/backup-restore-server/
Apart from that, you can check the log messages of the server initialization by running the commands below
sudo cat /opt/bitnami/var/log/*
The password shown in those logs messages will work in case it hasn't been changed.
Hope it helps,