What got me into kdrama was film first. So, you may want to try out action films, since they have very simple story and not super hard to follow.
1. Train to Busan (2016) - train, zombies, and passengers struggle to survive. The characters are very relatable and easy to follow.
https://mydramalist.com/11314-train-to-busan
2. Tunnel (2016) - similar to disaster films. collapse of a poorly constructed tunnel trapping survivors.
https://mydramalist.com/15793-tunnel
3. Masquerade (2012) - like the movie the man in the iron mask. A clown replaces the King to protect the king from assassinations. It's more light hearted than the iron mask.
https://mydramalist.com/4142-masquerade
4. Unstoppable (2018) - like the movie taken but instead of daughter, the wife is kidnapped. Lots fight scenes.
https://mydramalist.com/28824-raging-bull
Tv shows that are similar style to american dramas
City hunter (2011)- chuck but darker version. Revenge show for govt. coverup on spy mission killing main leads father. He works together with his father's friend to take down all those responsible.
https://mydramalist.com/1702-city-hunter-2011
Save Me (2017)- similar to the path, but slightly darker about cults. Follows a family that lost everything and joins a cult.
https://mydramalist.com/22599-save-me
Six Flying Dragons (2015) - a little more complex with multiple factions period drama. Lots good action scenes and story.
https://mydramalist.com/14324-six-flying-dragons