There may be opportunities for undergraduate students to participate in research within the RLAI lab, but to do so effectively you will need to be familiar with the basics of artificial intelligence and reinforcement learning. The best ways to do that if you are at the University of Alberta is to take CMPUT 397, "Reinforcement Learning". After taking 397, it may be possible to take Sutton's graduate course CMPUT 609, "Reinforcement Learning II". Another undergraduate course here that is highly recommended is CMPUT 466 "Introduction to Machine Learning".
If you are not at the University of Alberta, or unable to take CMPUT 397, then you can still take (or audit for free) the online reinforcement learning course taught by UofA professors and read and study the books "Reinforcement Learning: An Introduction" by Sutton and Barto and "The Quest for Artificial Intelligence" by Nils Nilsson.
The computing science department has rigorous standards for admission. Requirements include high grades, good letters of recommendation, and, except for canadian students, good GRE and TOEFL exam scores. For grades, we look for a minimum of 3.0 on a 4 point scale, but we also pay special attention to the quality of school at which the grades were obtained. For the GRE, we look for a minimum of 155 quantitative and 4.0 analytic writing. On the internet TOEFL, the minimum score is 100. Many students have difficulty obtaining a 4.0 in analytic writing and have to be excluded for that reason. This is a shame but appropriate; you cannot succeed in studies and in science here without being able to write clearly in English. It is better to take an extra year and improve your English than to struggle with difficult ideas in a language that you do not know well.
After you are admitted to the University and Department, you can begin the process of finding a faculty member to serve as your supervisor. In exceptional cases this is worked out prior to your arrival. More typically you arrive and take some classes, which enables the professors to get to know you, and you to know them, and then it is easier to find the best match. There are currently ten professors that are principal investigators of the RLAI lab: Martha White, Rupam Mahmood, Mike Bowling, Adam White, Patrick Pilarski, Rich Sutton, Csaba Szepesvari, Dale Schuurmans, Marlos Machado, and Matthew Taylor. Also affiliated with the RLAI lab is professor Martin Mueller and adjunct professors Martha Steenstrup and Huizhen "Janey" Yu (adjunct professors can be the primary supervisor of graduate students in conjunction with a regular professor). And of course their are many other AI professors in the department.