First, make sure that you're eligible. If you were hired roughly 3 months ago, you are probably eligible! If you've been around shorter/longer than that, you can't sign up until you become eligible; for partners hired more than 3 months ago, open enrollment is in August and this is your only time to enroll outside of a Qualifying Life Event.

You gotta go to $1 - I don't know if they changed the name but this link still works. Assuming they haven't changed the layout, there should be a spot for notifications/updated somewhere in the top right corner of the page. I'm pretty sure every time you're eligible to enroll, be it open enrollment or new hire, they put a little notification window in the top right to let you know.

Otherwise, there should be a spot in the navbar or a way to get to the health insurance section from the main page, after you log in.