To find a member in MORI, go to Membership > Find Member in the menu. You'll see a screen like the following:
The search form contains fields for Last name, First Name, Member Number, Lodge, status and member type. There are additional parameters that are excluded (-) by default. They include: by distance, by birth date, by notes, exclusions, some "other" parameters and the ability to add your search results to the Mailing Screen buffer.
As you can see in this example, when it comes to searching by name, less is definitely more.
To get to the desired member record, simply click on the name of the member. During the same session of using MORI, previously visited member records will appear on the find member screen whenever you return to it.