Show most used items when I open Bitwarden

Is there a way to have the most used items show up when I open Bitwarden?

Not that I know about. However, if you are using a browser extension and have added the URIs for your items you will be presented only with matching credentials. The one used the last time will be the first on offer.

Good advice from Peter above. You can also designate Favorite items that will appear at the top of the list on the Vault page of the extension: