In order to select a Vercel team from your Vercel personal account's dashboard, click the Select component in the top left of the header.

After toggling on the Select component, you should see a list of the Vercel team(s) you are a member of. Select the Vercel team you wish to navigate to.
NOTE: Your Vercel personal account is your connection to a Vercel team. Deleting your Vercel personal account will prevent you from accessing the Vercel teams you are a member of.