To join Discord server, create an account and login. Then from the Account webpage click on “My Profile” and click on the green “Join Discord” button.
You can also click on the “Login” or “Discord” webapge from the top menu and it will take you to the Discord webpage where you can click the green “Join Discord” button.
To get Discord Alerts sent to your phone just like a text, turn on your phone notifications for the Discord app and in Discord turn on notifications for the channel(s) you want.