I'd probably be dead in no time for a long list of reasons
First of all, nobisy would be able to understand me, as even current English would be barely recognizable by them
Then there is the issue that I'm probably at least a foot taller than most people and let's just say that "being even remotely different" back then was a good reason to be killed
Then there is the food issue. Food was scarce (hence most people being quite a bit shorter than me) so it'd be hard to keep myself fed. Clean water? Hah, good luck with that.
Then there is the issue of diseases. I probably carry shit that their bodies won't be able to handle, si being around me will likely make people sick, which in turn will get me labeled as a witch which would get me tortured and burned. Similarly but conversely, loads of diseases that were rampant back then are now gone, and likely my body is less equipped to handle that, I'd die from some disease
Ignoring all of that...
I'd probably start spreading the knowledge of democracy, and the harms of religion, and how important it is to immediately kill kings or king wannabes. I'd make a library with a vast wealth of knowledge and give access to the first country that successfully transforms itself to a representative atheist democracy with laws in place to ensure that no king, fascist, or wannabe will ever be able to rise up again.
That country would become the dominant world power within decades, spreading democracy and science over the world.