Adding sounds and images are pretty easy, making them "fit" is harder. To add sounds go to "Table"/"Sound Manager" (top of the editor) and you will see all sounds that are in the table. Assuming it's a VP table and not VPM, you can also "Export" them out (a copy) to wherever and use them in another table. Use the "Import" and browse for sounds to add to your table. You can make them play by using the command: Playsound "addyoursoundhere". That name must match the name in the sound manager or it will not play.
Overlapping sounds: Here is how you keep sounds from overlapping one another.
Sub Toplane_Hit()
Playsound "toplane"
End Sub
Checktoplanes()
If Toplane1.state=1 and Toplane2.state=1 then
Stopsound
Playsound "toplanes completed"
End If
End Sub
Sub Stopsound()
Stopsound "toplane"
End Sub
Say you want to play the toplane sound, but if you complete all toplanes you don't want the completed sound to be drown out. So you put the playsound "Toplane" command in when you hit the toplanes, then you call the stopsound sub where you check if all toplanes are hit. This plays the toplane sound, then stops it when all lanes are hit so it can play the completed sound.
Images are added/exported the same way. You will see a colored rectangle below your image, this is the transparent color. In other words, the editor will ignore this color. A great example is a ball image. A ball image is the ball with a background color. Set the transparent color to match the background color and all you see is the ball itself, not the whole square image. Caution: Make sure to set the transparent color to a color NOT in your image ANYWHERE. Otherwise your image will be blotchy due to a missing color. Images are used for lights and walls.
It's best to export a blueprint and paste your image to the blueprint. Go to "File"/"Export Blueprint" (Top left). Paste your image to that blueprint. Keep in mind the size of the image vs the size on the blueprint. The size will have to match up or the image won't look right.