Hi Jessica, welcome to the world of kdramas! Your life will never be the same again.
Here is my list for you:
1. Signal (Time travel, Detective, Crime, Suspense)
2. Stranger (Thriller, Crime, Law)
3. Weightlifting Fairy Kim Bok Joo (Friendship, Romance, Slice of Life)
4. Healer (Romance, Action, Mystery, Thriller)
5. I Hear Your Voice (Law, Crime, Thriller, Romance, Supernatural)
6. Tunnel (Thriller, Psychological, Sci-Fi, Detective, Time Travel)
7. Circle (Mystery, Thriller, Sci-Fi, Detective)
8. Six Flying Dragons (Thriller, Action, Historical, Psychological, Romance, Political)
9. Goblin (Fantasy, Romance, Comedy)
10. It's Okay That's Love ( Psychological, Comedy, Romance, Emotional)
These you should start out with. All these have finished airing. If you are interested in a drama which is still airing, check out 'While You Were Sleeping'. It ticks all the boxes on your list of genres,
P.S.: Goblin, SFD and IOTL are my personal favorites. The only reason they are at the end of the list is that I didn't know whether you would be interested in them. But all three of them are amazing dramas, capable of making you cry, with stories and characters strong enough to haunt you for days after you've finished watching them.
Happy Binging. :)