EDIT: Problem solved, and - ahimé! - it was so easy. Posting this for other users, just in case:
This is how I proceeded to remove the blank sequence:
1. Uploaded a new file from the Upload File icon in the menu.
2. Drop the new file (video) in the Sequence(s) Field. Here the blank sequence will appear as the 1st one.
3. Used the red vertical liner: moved it to the end of the blank sequence, then dragged it backward in order to select (the selected area appears in a blue transparent color).
4. At this point, a menu with tools appears next to the selected area: used the bin to completely remove the sequence.
That was all.
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Hi, Nat!
Thanks for the clarification above, it helped until a certain point whilst having the problem mentioned in this topic (sorry if I missed something, my experience here is of a basic level yet).
Nevertheless, I am still stuck at understanding how to remove this blank "0" section? It doesn't appear in the "section raw" and brings back always a portion of a video (into the new one) that is even deleted on my pc and doesn't appear in Projects folder ( I am sure I've never saved it, but just double-checked for an automatically saved one, in case it might have happened). Now, if I try to remove that part (in sequences), it reappears all the same a bit later overlayed on the second sequence of the video I am working on.
The mentioned blank and blind section doesn't appear in other files I upload, only in the first one I've tried when encountered the issue.
Note: I proceeded as regularly, as on any other video editing process, and it never happened before.
Hope very much it makes some sense what I've written above 😕 and thank you in advance for any help pn this.