Hi
OK. Start by finding and then loading your MPEG clip to the Media list by using the "Add Media" button.
Now left click the clip in the media list window and then drag it down and drop it onto the sequence line. It will preview in the left hand window as soon as you grab it and once released on the sequence line it will appear in the right hand preview window. The left hand window will then go blank. The soundtrack for the clip will appear underneath the clip on the Audio track.
I personally feel its better to set the sequence line to storyboard mode as you can see your clips more easily.
If you now click on the clip in the sequence line it will preview in the left hand window.
Note that the right hand window previews the cursor position whilst the left hand window previews the clip.
For the moment ignore the red/blue in point/out point markers.You can use these to precisely cut your clip in two places in order to isolate a section but you can do this as described below.
You can play your clip using the "Play" button in the RH preview screen.
If you want to cut your clip in two (or more) then play the preview (RHS) and stop where you want to cut it. Step forwards/backwards using the < > tabs to be more precise and then click the "Split" tab on the far left.
This will create two clips on the sequence line and either can be removed by left clicking the one you don't want to select it, and selecting "Remove selected clip". A second split using the same method will isolate the bit you wish to keep. If you dont remove any of the "bits" you create you can move them to another part of your film by simply dragging them to a new position. Its the equivalent of making a new clip.
Save as a new clip means that the once you have selected in and out points in the LH preview window the section under the green bar is saved to the Media list as a separate clip. ( not the PC.) Before trying to save your sequence to your PC check it plays as you want it to in the RH preview window. But drag the cursor line to the start or click the << button.
If it plays OK then try saving it to a folder on your PC.
I am not sure why your audio played without a video but try the above steps for a start.
Regards
Nat