What "alphanumeric" means here
Letters and numbers together: account numbers like AC-40917, names written as โLast, Firstโ, phone numbers with dashes and amounts with commas. Tests check that every character, including punctuation, is right.
How it's scored
Most data-entry tests score keystrokes per hour (KPH) and accuracy. Here, KPH counts the characters in fields you got exactly right, scaled to an hour. Convert to WPM with the KPH calculator.
Practice tips
Read a whole field before typing it, use Tab to move between fields, and don't look back at finished fields. Numbers-only tests are different, so practice the 10-key test too.