For a short flight, yes.
For a long flight, no.
The longer you are in space, the more training is needed to be there. For a very short trip, it'd be little more than riding as a passenger in a fast plane (and G forces are in tolerable ranges. A bit intense, but nothing the typical healthy human can't handle.)
The first hard part is fears. Unless you're an adrenaline junkie (as pretty much every astronaut is; every astronaut is an experienced diver, fighter jet pilot, and more), the entire process can be immensely fear-inducing. Anyone with a fear of heights is obviously going to have an issue. And once you're in a constant state of free-fall... well... expect at least one untrained person to be screaming. This can be annoying at least for the other passengers and the astronauts.
The second hard part comes with farting (seriously). In a car, boat, or plane, it has a tendency to linger more than in a house or outside, but it still dissipates. That's because none of those things are sealed air-tight; fumes still escape. In a spacecraft, you're stuck with every fart, so proper knowledge of how to handle that is necessary, suits and filters.
The third hard part comes the moment someone needs to go to the restroom. Going to the bathroom in space requires training, because one of the most dangerous things in space is floating liquids (and if you try to use the restroom without proper training, you could actually be at risk of bringing down the entire shuttle due to your fluids getting literally everywhere.)
Then comes eating and drinking. Also challenges in zero G, and again, there's a huge risk if fluids or dust start floating about. Fluids can corrode and/or destroy important electronics, and any kind of dust can wreck havoc with ventilation systems.
The list gets more complicated as things go on, including higher than normal exposure to radiation, how to handle moving about the cabin, and more. Humans are not good at staying stationary for long periods, and will soon need how to interact with a lot of their environment.