If you have windows, the videos automatically save to Documents>Bandicam as a .avi file after you stop recording. If you wanna record audio i think you need to have a connected mic, i've never tried it with my computer's built in one
If you have the free version, there's gonna be a watermark that's a considerable size that says "Bandicam.com". You can't remove it unless you buy bandicam. I just record a little more of the top of my screen and crop it when i edit my videos. also, the free version has a recording cap of 10 minutes, which means you can't record more than 10 minutes at a time.