The type of RV you should rent depends on how many people you are travelling with and where you intend to visit. Some people may prefer a smaller vehicle that is more maneuverable. Alternatively, if you are travelling with a group you will need a larger vehicle to accommodate everyone.
Smaller vehicles (sometimes called campers) generally sleep 2 adults. These vehicles tend to be easier to drive and park, but may lack certain amenities. Some may not feature bathroom and kitchen facilities, so you will need to find RV parks that offer these facilities. If you want to be self-contained on your Canadian holiday, you may need to look at larger vehicles.
Motorhomes are larger vehicles, and tend to accommodate more people. These vehicles offer more storage, and also feature amenities such as a shower, toilet, kitchen, washer, dryer and more. Motorhomes are generally more expensive than their smaller counterparts, and can be more difficult to drive, particularly if you're not used to navigating the roads with a larger vehicle.