Welcome to Canvas! You can do this through the inbox. Compose New Message, select your course, and then in the "To" select "All In Course." You can also differentiate by sections, groups, and roles.
Hello there, @hancuffj Welcome to the Canvas Community. Thank you for posting your question. Here is a helpful Guide for you: How do I send a message to all course users in the Inbox as an instructor?. Please note that Canvas technically does not use the term "e-mail". Please check out this response from a past discussion for more details on the terminology: Sending email to students. I hope this extra bit of information will be of help to you, Cody.
Hi @hancuffj I generally use the announcements feature to do this in my Canvas course. I prefer this format over using the "inbox" because the message also lives in a space within the course, just in case students turn off notifications or do not check their student e-mails (This happens alllllllll the time). Feel free to review both links below for more information on using Announcements in Canvas.