A typing test asks you to copy a passage while the clock runs or while a word target counts down. When you finish, you see scored WPM, raw WPM, accuracy, and errors. Most people use sixty seconds as the standard minute: long enough to show real rhythm and short enough to repeat every day.
Use a 15-second sprint to warm up, a one-minute test for a score you can compare week to week, and a two-minute or 100-word run when you need endurance. Quote mode trains full sentences. Custom mode is for names, codes, and exam vocabulary that generic passages never include. Language can be changed on the test page, including native script with your system IME.
WPM here uses the usual five-character word, spaces included. That is the convention most public typing tests use. This site is practice, not an official government exam, so treat your result as training data. Aim a little above any cutoff you care about, and keep accuracy high.