I have been trying to visit my long-term girlfriend for the past 3 years. Because I have a criminal record (I was never sentenced to a prison term) I cannot get an eTA. Is it possible for me to fly there with just my passport, so that I can wait for her at the airport and fly straight back with her? She is terrified to fly alone, as she has autism.
If you're not eligible for an eTA, you would have to obtain a visa. Without that, should you be allowed to board a flight, your arrival in Canada may not go smoothly, and your plan may be disrupted or fail.
If you're admissable to the United States, you could meet at the USA-Canada border, which has more than 100 crossings. She could use ground transportation (car, bus, train) to get to the Canadian side, you would wait for her on the US side. You could then travel together to your destination.