I'm fairly new to lightroom. I'm trying to import my photographs from multiple locations in Lightroom. However; when I use the import option in Lightroom, the whole catalog of images I previously imported gets wiped out and replaced with the last selection I imported? - Do you have to manually create a folder with your images/videos in, or can you 'add' to a catalog instead of an import replacing what was in your catalog originally.
Many thanks in Advance
In the import dialog, if you have the "skip duplicate files" checked, the files you previously imported will not be displayed to you.
In the Library module, there is the "previous import" group, which changes with each import you do.
If you are not creating your own groups to put the images in, the folder tree will be the way to find them.