Welcome to the forum.
Unfortunately, we need a lot more information to try and help.
The first things that I would concentrate on would be the source AV files, with full details.
Next, what is your Project Preset.
This ARTICLE will give you tips on other useful info, plus tell you how to get the info on your source footage.
"but there is no video on playback."
Could you please go into further detail on that? Do you mean by that, with your video on the Timeline, when you press the Edit Mode Monitor Play Button or press the computer Spacebar, there is a blank or black Edit Mode Monitor? Or do you mean, that you see the first frame of the video in the Edit Mode Monitor, but, when you go to playback the Timeline, the Timeline Indicator does not move from the start of the Timeline?