Help this layman understand "scrapers," "scraping," and more.

[banjoboi420]

My collection stems from many different sources, and so far I'm not getting any scene, photo, or movie matches. This is the feature that made me want to try out Stash over Plex (what I currently use), so I'd very much like to take advantage of it. But I'm very close to being an utter layman when it comes to these kinds of topics - I'm sure I'm just doing something wrong, and I need help finding out what it is.

Does anyone have a thorough guide or even just pointers on how to achieve thorough scraping? I'm not even getting automatic performer tags, even when the performer is listed by name in the associated filename.

Thanks in advance! And thank you devs for an awesome solution to my stashing needs ;)