Your first test (on Parts 1 and 2) must be taken during the period February 11-14. Read the Tests page for details on how tests operate.
A sample test will appear in your current WebAssignments on Monday, Feb. 3. This sample test will be like the "real" test in that it will be limited to 75 minutes and 3 submissions for each question. So it gives you an opportunity to see what the real test environment will feel like. Don't open this sample test until you are ready to make use of it. The "timer" will start as soon as you open it, and the test will "close" 75 minutes after you first look at it.
The sample test is optional. It's not counted as homework or for any other grading purpose.
Tests require a password. When you take the real test at the DE Proctoring center, the password will be entered by the proctor. With the sample test, the password is "sampletest" and you can enter it yourself whenever you're ready to do your practice session. But remember since your 75 minutes will start immediately, don't open the practice test until you're ready to use it.