Your question is confusing me. You said............
"How do I erase an extra dashboard that is up"
First, a Canvas account only includes one Dashboard, and that is the page/screen a user is taken to after they log in. You should not have two dashboards unless you have two Canvas accounts.
Secondly, you said..........................
"the other one has all my work in it"
Unless you are an admin who posts global announcements, the Dashboard for a Canvas account does not display a user's work. A Dashboard typically displays:
- Global navigation menu,
- Announcements pane,
- Course Cards (in Card View), or
- Recent Activity (in Recent Activity view), or
- List View.
- A To-Do list,
- A Coming Up list,
- Recent Feedback area,
- Start a New Course button, and
- View Grades button.
If you are asking about how to change the view on your Dashboard so that it no longer displays your course cards, then this guide will help https://community.canvaslms.com/docs/DOC-10587-4212710330
If I have misunderstood what you are asking for, let me know so that I can better help you.