Hello there I am totaly new here also in a Inkscape
I have one picture 187x96 cm and I would like to mill this pic with my CNC but my CNC is only 300x200 mm so will have to kind of split the pic
into many small ones . How can I do this?

Thank you

Depending on the specific image, and where it might make the most sense to break up the image, you would either need to use node editing, or maybe a path operation like Cut Path or possibly Division. Or maybe a combination. If you'd like advice about the best place to break up the image, can you show it to us?

Sorry, but I come from the backwards place in the US, where metric isn't out native system. How many pieces will you need it cut into?

Wait, if the CNC is smaller than the image..... Do you mean you want to cut out a lot of small pieces of wood (or whatever), and glue them together later? Or do you mean that the screen of the CNC is smaller, but you can cut out of a whole piece of wood? I guess that wouldn't make much sense.....