There are a few things that may be keeping you from logging in. The best thing to do is check what message you get when it doesn't let you in.
"Invalid username or password."
If you see this while trying to log into Canvas, either your username or password is wrong. Check the login credentials that your school sent you and make sure to type everything exactly the same. If you've lost that information, you can reach out to your school or your class facilitator. They can look up your account and send you your login information again.
Something else to note is that you need to make sure you're trying to log into PLI's Canvas site. If you see something other than "Proximity Learning" on the page, and something other than "https://proximity.instructure.com/login/canvas" in the URL bar, then you will not be able to log in.
If you still aren't able to get in after making sure you're in the right spot with the right username and password, click Tech Support and let the Solutions team know that something is off. When you do so, make sure to include information about yourself so that they know they're looking at the right account. At the very least, please include your first and last name, student ID, and the district you attend. That way, Solutions can quickly and safely find your account and help you get logged in.