I am visiting Canada for 3 weeks. I have a Netherlands passport. I will be arriving by air, and have applied for and received an ETA. I was wondering if anyone else on here has visited Canada with an ETA and can tell me what happens at immigration at Canada? Do they ask a lot of questions? Do they ask to see your return ticket, proof of stay (hotel/letter from a friend), proof of funds etc.? And is there a form to complete at immigration?
Canada isn't significantly different from other Western nations. The degree of questioning is going to depend on a number of things, many of them intangible. Some luck may be involved. You should be prepared to answer all the questions you mention, and be prepared to show return tickets, bookings etc. However the number of Dutch people trying to enter illegally is pretty small, and it's unlikely to be a lengthy interrogation unless you stand out from the crowd in a bad way.
The only form to fill in is the landing card, which you will be given on the plane.