I spent all morning working on a file in Inkscape. I'm a beginner but I know that I created 3 layers, made a lot of vectorized lines (if that's what it's called), imported 4 pictures, and resized the drawing. Now when I open it there is only 1 layer, no pictures, but the picture is the size I resized the drawing to.

Any suggestions?? I am already in a rush and I do not love the idea of redoing the whole thing! Also how do I know I won't make the same mistake again??

That sounds bad.
Good thing is it still opens.

Maybe you linked the raster images, then put the images into another folder? Should display a "linked image not found" icon then.

Not sure on what you were doing, so cannot suggest anything specific.
In general inkscape is not a raster editor, maybe you can use something like gimp with better luck for the task.

Can you describe your work more -show screenshot/share file/design idea...?

It really is impossible for us to have any idea what might have happened. We can really only ask dumb questions. Like:

Are you sure you saved it?
Are you sure you're opening the same file you saved?
For the file you opened, are you looking at 100% zoom? Did you draw at 100% zoom? If you drew the image while at high zoom, it may be so small you can't see it. If you drew the image at low zoom, you may be looking at the inside of a tiny portion of the drawing (and the rest of the drawing is huge, relative whatever zoom factor).

Did you by any chance hide any of the layers? If you clicked (accidentally or on purpose) the tiny eye icon beside each layer, then that layer is hidden. Look and see if you see the open eye icon or the closed eye icon.

If you still can't find your work, try this. Close the file and open it fresh. Make sure all the layers are showing (open eye icons) Hold the Ctrl key while you press the A key once. That's the shortcut for Select All. Then look at the status bar and tell us what it says.

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More questions

Did you save an SVG file? Or did you export to another format?

Try setting the opacity to 100. That solved my blank page problem