When you go to the Simulation page, there are three options:
Learn Mode, Practice Mode, and Test Mode.
Learn Mode uses hints and color cues to guide you while you are learning.
Practice Mode lets you take a practice test.
Test Mode is the final stage, where you can show your knowledge of the procedure. Note that there is no guidance or tips, and you will be given a simulation scenario at random. So make sure you have used Learn Mode and Practice Mode first, to familiarize yourself with all of the scenarios in the module, then you'll do great!
Click on Start Test to launch a Test Mode scenario. Note that the system will choose a scenario at random for you - you can't choose a specific one in Test Mode - but as long as you have previously done all the scenarios in Learn Mode and Practice Mode you will be fine!
By the way, if the Test Mode section is greyed out so you can't click on Start Test, this means you have the simulation scenario selection window open for Learn Mode or Practice Mode. Close that scenario selection window by clicking on the X in the top right corner of that small window.
Let us know if you have any additional questions - happy learning!