As a powered parachute sport pilot applicant, you must take a 40 question multiple-choice test and score 70% or better. There are separate tests for each category of aircraft with many similar questions for all the LSA categories. The FAA has approved two test providers LaserGrade and CATS. The test must be taken at an approved test location. Both LaserGrade and CATS have franchised hundreds of test locations around the country.
The FAA has published a sample of the test questions you can expect to see on the 40-question test. Here is a link to FAA Airman Knowledge Test Question Bank (pdf).
The problem with using the FAA raw test questions is that they are out of order and there are no answers. The easiest way to prepare for the exam is to use the ASA Test Prep materials which provide the questions as well as answers and explanations of the answers.
You should also find our answers to the most frequently asked questions about preparing for the FAA knowledge exam for the sport pilot airman certificate to fly powered parachute light-sport aircraft (LSA) very helpful.