If you search for pencil drawings and study how to recolor them & add the right background paper image in graphic software you'll have more options than by searching fully ready results. There's no need to shell out money for programs. Freebies such as Paint.NET and GIMP can both do the recoloring. Inkscape is useful for your own vector drawings, but not a must. I guess in a week you can do the modifications by yourself and nothing prevents you to ask help. It's our hobby.
I guess high quality drawings generally aren't free.
This is an example of the recoloring:
It's made of 2 images which both were black or grey on white. There are 2 layers, the top layer (=boat) has got a little different recoloring than the bottom layer. The white areas in the boat image are selected and deleted to make the grid visible. The image is copied from this wikihow article: https://www.wikihow.com/Draw-a-Boat
I guess nearly any drawing with visible pen texture will do the job if the subject is the wanted one and you recolor it to ballpoint-pen color. Even some simple enough photos which are filtered to have drawing like texture and single color can be plausible enough