You can access Microsoft Teams two ways. Either throught the browser or by installing the client.
Install the App
To install the Microsoft Teams client software or App, please follow the instructions contained in the Installing Microsoft Teams KnowledgeBase Article.
One of the benefits of using the App is that it remains logged in on your device and can display alerts when they come through.
Access through the web
To access Microsoft Teams through any web browser, navigate to https://teams.microsoft.com/. Enter your MESC email and password to login.