Possibly [The Cineverse Cycle](https://www.goodreads.com/series/95250-cineverse-cycle) series by Craig Shaw Gardner?

- Slaves of the Volcano God (1989)
- Bride of the Slime Monster (1990)
- Revenge of the Fluffy Bunnies (1990)

> Roger Gordon's life was dull until a Captain Crusader Decoder Ring unlocked a door to the world of B-movies. Now his life is filled with adventure as he frolics through the silver screen's weirdest westerns, thrillers and romances. 

Roger finds himself within a universe filled with people, situations, and tropes from B-movies. For example, he picks up a sidekick, who explains the situation about sidekicks:

> But Louie wasn’t convinced. “It’s not that simple. We may be good guys, but we may still just be sidekicks, too. And sometimes sidekicks get killed.”
>
> “Killed?” Roger replied with some disappointment.
>
> “Yeah, it’s called pathos. It helps move the plot along.”
>
> Roger sighed. “And anything that moves the plot along is Movie Magic?”
>
> Louie nodded in approval. “You’re learning fast. Besides, you can never tell when the bad guys will run out of bullets. That is, until it happens.”

For another example, Roger finds himself in a setting from a foreign "art" film, where very little seems to make sense, and he can actually see English subtitles for the incomprehensible language the other people are speaking. He uses these subtitles to try to form a sentence in the unknown language, and gets it pretty hilariously wrong:

> Silently he formed the question in English: “I must see Captain Crusader. Where is he?” It was simple enough. Surely, even though the words might not be in the right order, the sense of his question should get through.
He coughed rather loudly. Both Piers and Katrina turned to look at him.
Roger spoke quickly:
>
> “Storg gnurden Captain Crusader. Minsky smeltzny valarie?”
>
> Both Piers and Katrina stared at him, open-mouthed.
>
> This was not quite the reaction Roger had been hoping for. His eyes slid down to the subtitle before him:
>
> YOUR SISTER HAS DOG BREATH. AM I CAPTAIN CRUSADER?
>
> Piers turned to Katrina. Roger was too upset to listen to what the haggard man was saying. He couldn’t help himself; though. He had to read the subtitle.
>
> HE HAS MET YOUR SISTER.
>
> Katrina’s reply was angry. Once again, Roger didn’t really listen, but only read:
>
> I HAVE NO CONTROL OVER HER PERSONAL HYGIENE.

By the third book, Roger comes to accept that he is, in fact, Captain Crusader in this universe, and therefore the hero.

In my opinion this series is thoroughly hilarious.