Wanting to purchase an iPad and apple pencil

For work I have to annotate pdf documents, which often requires me to use a separate program to digitally draw supplementary images on my laptop. If I was to purchase an iPad and apple pencil, would I be able to annotate pdf documents with the apple pencil, and could I add in blank pages? and if I do annotate a document, if I send this to a computer user, or a non-mac user, will they be able to read the annotations?