I'm starting to use inkscape and have the following problem.

I have inserted a photo which I want to copy in a new layer.
I only want to copy the lines in the photo which I want to use.

does anybody have an idea?

thanks

Welcome to InkscapeForum!

The photo is probably a JPG, which means that Inkscape can't edit the image. The image will have to be converted to vector, before you can begin to isolate parts of it. There are 2 ways to do that. One is using an automated trace, such as Inkscape's Trace Bitmap (Path menu). It depends which options you use to do the trace, that determines how to select individual parts. If it's a black and white photo (or the lines that you want are black on white) I would suggest using a single scan. Then you would use node editing to isolate the lines.

The other way is to trace the lines "manually" using the Pen or Pencil tool. In that case, you would not need to do lot of node editing, since you'll be drawing only the lines that you need.

I don't know why you want to use Inkscape. It may be that you need the vector format. But if you don't, this project might be better done with a raster graphics program.