Most Linux distributions offer a “live CD” experience (does not actually have to be on a CD nowadays; you can use a USB drive). Basically when the computer turns on you tell it to boot off the USB drive instead of the drive in the computer. That way you can try it out on your computer before installing it and see if it works out of the box for you with its defaults. It will probably be a little slower running off a USB drive. I don’t think you can typically install additional programs or save things to the computer (someone more experienced might chime in), but you can try doing basic things like using the web browser or word processor.
Most Linux distributions offer a “live CD” experience (does not actually have to be on a CD nowadays; you can use a USB drive). Basically when the computer turns on you tell it to boot off the USB drive instead of the drive in the computer. That way you can try it out on your computer before installing it and see if it works out of the box for you with its defaults. It will probably be a little slower running off a USB drive. I don’t think you can typically install additional programs or save things to the computer (someone more experienced might chime in), but you can try doing basic things like using the web browser or word processor.