To search for a contact, select the contact icon (teal ID card) from the top menu bar. 
...
From the contacts page a simple contact search can be done by typing all or part of the contact's name into the search field. 
...
A more advanced search can be preformed performed if necessary by selecting 'Advanced Search' and adjusting the fields. You have options for the name, what Legal Entity Type it is and whether it is active or not.
Warning: By default only the Active clients are shown
...
You can perform a new search be selecting the Reset button.