Great questions and answers from locals that understand the market and have a keen level of experience. I do recommend that you learn the ropes yourself. I think interacting with tenants is a very useful experiential learning opportunity. Lean on your network for help with reviewing any tenants that you feel are worthy of renting your place to, for security.
I use credit quality and affordability metrics to ensure that prospects can afford the rent. You should begin to establish a process for evaluating your rental market, your advertising, process for interviewing tenants including a formal series of questions. In addition, you should understand how to extract critical information from prospects that will allow you to make good decisions on leasing.
Standard Ontario Lease is required, but you should start to think about all the terms and conditions that are not included in the standard lease and prepare to include them in your agreement. I have several specific terms that i include, which are highlighted and require initialling so that I have some form of proof that they were aware of those conditions. You will build up a very good list of terms to add as an operator of rental properties.
Red Flags - tenants that can answer everyone of your questions. Pro's know exactly what you want to hear. If it is too good to be true, then usually it is. "I make $10k per month but have a 480 credit score but I pay my bills on time."
Repairs and maintenance or very tricky to enforce. Discuss with tenants what represents normal wear and tear and what does not. I always maintain a fund to fix damages, both accidental or negligence. The downtime, legal costs and that "kicked in the privates" feeling from trying to extract damage money from a tenant is not worth it. Inspect your properties often. Use fire safety inspection as way to get in every three months. This way you can have hard conversations with them sooner rather than later.
Good luck with land lording. It is the only way to economic self sufficiency that I know.