where do people find designs (2d) of complicated projects like tractor or car......is there any book??

I am also looking for some assembly drawings with dimensions to learn CAD especially solidworks.

Hi. There aren't any books. If I want to design an Excavator Dredge Pump Attachment, I'll reach out to manufacturers and request that they send me a catalog of their products, the catalog gives me a good idea of how the final component should look like. I'll then request for operation manuals, maintenance manuals and attachment drawings of the component.

These manuals don't have the dimensions, but do have the name of the individual components, like bearings, pins, clips, bolts, nuts, materials of components.

I'll then google all these components individually to get their dimensions. It's a tedious process but it's what I have to do when I want to develop a new product.

I hope this helps.

I'm used to look for blueprint sheeps on Google.
like, if i wanna draw a car, just tab "car blueprint", on Google images.

https://www.google.com/search?q=car+blueprint&sca_esv=581287324&rlz=1C1GCEA_enBR1069BR1069&tbm=isch&sxsrf=AM9HkKllMl7vm40V4nM65Ljhql_GOpPsXA:1699645449498&source=lnms&sa=X&ved=2ahUKEwiVsIvamLqCAxVCLrkGHaDfBowQ_AUoAXoECAIQAw&biw=1920&bih=963&dpr=1