If you ask anyone who worked at Rona the worst part about the job would be the management, regrettably.
The other employees who do work there are nice but management not so much. They can be unprofessional and some are disrespectful. The store its self is one giant hazard for its workers for example leaks, equipment failures, no proper training, the management was not prepared for emergencies like fire alarms and ignoring to fix certain broken equipment or simply not providing them at all. Some of them do not have any knowledge about their departments, so you're completely on your own. Always understaffed, which is annoying to customers but is stressful for their own workers.
The hours are also very inconsistent, you'll get 40 one week but 10 the next.
The overall culture isn't so bad, you'll definitely make friends quickly the employees are all amazing and Rona is definitely diverse with all ages, genders, and workability.
Summer is Rona's prime (unless you work in the plumbing department which is understandably an all year round thing) but you will notice the extreme work decline in mid-October through to mid-April.
For a first job, it would be okay, but not long term.