Although I think most prospective grad students have been told about the importance of picking a study/project that interests you, I think it's also really important to take some time to see how you interact with your supervisor and lab. These will be the people you work the closest with for the next several years, and help provide support to you in some of your toughest moments.
Absolutely take the time to reach out to current students, alumni, and faculty members affiliated with the grad programs of consideration. Your grad school experience will very much be influenced by the people you are surrounded by during your education and the culture of the program. Hearing from other's experiences and talking to current students is one of the best ways to find the right fit for you.
Always ask for help. When in doubt, ask; When not in doubt, ask. Enrolment in graduate courses can be very small, and grad life can sometimes feel isolating; so, try to form great bonds with other grad students. You have a lot in common! Try to take some time off to have fun, and when you inevitably encounter students pulling a tractor in September, do the opposite of what I did; and be cool! If you can, participate in the 3-minute thesis competition (3MT); it's a lot of fun!
I've been very privileged and lucky since coming to Guelph for my undergraduate degree back in 2010 as all of the opportunities I have been given have been gained through building strong relationships with faculty and staff on campus and finding mentors that have helped guide me along my career path. I've always found that the people on campus are incredibly giving and willing to devote their time to help out students. I've also found that simply starting with expressing an interest to be more involved and showing initiative can go a very long way to opening doors to new opportunities.
Workshops offered through the library and OpenEd are so beneficial to help with your research goals and teaching tips/tricks. Definitely be sure to check these out!
I loved being a PhD student here. My advisors and labmates were all very supportive of my research endeavors. I enjoyed being in charge of my own research project.