Hi, email@example.com, and welcome to the Canvas Community! The most likely cause of this is an out-of-date or unsupported browser. Please review Which browsers does Canvas support? and compare the listed browser versions to what you're currently using to access Canvas; if you're using an older browser, you will most likely experience issues.
If updating the browser doesn't solve the problem, please contact Canvas Support for additional assistance (How do I get help with Canvas as a student?)
I'm not sure if you realized it or not, but you posted your question to the global Community of all Canvas users. As such, we don't have access or information about class or school specific information/policies. For this type of question you'd want to contact your advsior, registrar or schools help desk to inquire when enrollments for the upcoming semester will be done in Canvas. Once enrollments have been pushed into Canvas the courses should populate automatically on your dashboard.
You may also want to check to see if you're already enrolled in the course, but the course is set as a future enrollment because the term hasn't started. You can do this by following the steps in this documentation (https://community.canvaslms.com/docs/DOC-10596-4212710333 )