I'm new to this program, so pardon the newbie issues.
1. Is there a basic user manual?
2. What type of images are best to import?
3. When I import a PNG I don't see it. Stays a black screen.
4. When I imported an SVG file I see part of the image in the upper right corner. How do I drag it?
All I really want/need to do with this program is import images I've already created and then export them as a DFX file.
You can not really import an image into LibreCAD and export it as a dxf file. It's only a reference to an external image file you have to carry along with the dxf, preferably in the the same folder. Why do you want to "convert" a bitmap file to a dxf, which is a vector file, this makes no sense. More background information please. There are raster to vector converting apps, is this what you are looking for? But this is only a makeshift.
https://wiki.librecad.org/images/2/20/LibreCAD_Users_Manual_2.1.3.pdf Not basic, but less is not useful.
PNG is fine.
You might try zoom all.
You can drag an image like any other object.
You might be able to see your imported graphic then.
A dxf file can not describe a bitmap, pixel graphic like png. As I explained, when imported the image is not really incorporated into the file, but only referenced to, just the path to it and the position and scaling written into the dxf. So what is the sense in offering an otherwise empty dxf plus the bitmap file instead of only the bitmap?
What does the cutting machine cut, the cloth for the Tshirt or a kind of stencil for printing or airbrushing the graphic? The latter would only work if you have monochrome, like pure black and white, graphics with clean borders. You need a vectorising, tracing software then to make a dxf from it. You may try inkscape, it has a vectorizer. Or the free version of WinTopo.
Or are you having trouble with importing an image at all? Don't know where the problem could be. After selecting the image it's at the cursor and you can place it anywhere with a left-click. You can zoom in and out during that with the scrollwheel. You can scale it afterwards with Tools - Modify - Scale. It then seems disappeared but Autozoom brings it back. You can also make import settings in the Tools Options bar.
You may provide a sample file of yours if you like, to examine the problem more.