Hi @RavynDavis welcome to the Canvas community !
Have you checked whether the students appear in the People view ?
This sounds like an enrolment issue; assuming that you have centrally managed enrolments you would need to have a chat with your admin team to make sure students are being assigned correctly.
You need to avoid getting to the end of the semester to find that students don't have access - New Analytics will tell you if students are making access (you. might look up the errant students there). You should also think about mandatory session 1 Canvas activities that students must complete in the session to iron out any enrolment wrinkles at the very start.
One further possibility is that the student dashboard has been 'crowded out' - students should click on Courses to view what is available and select or deselect for their dashboard.