Where to start: Spotify. They have tons of 'Top 40' playlists and stuff like that. It's a pretty easy way to listen to new music - they even have a playlist called 'New Music Friday' which they update every week with new stuff. I'm listening to that right now as we speak.
My fav 'new' stuff:
Post Malone
Chance
Kendrick Lamar
Marina and the Diamonds
The Pretty Reckless
Barns Courtney
Twenty One Pilots
Sam Smith
Cardi B
Halsey, Camila Cabello, Machine Gun Kelly, Ed Sheeran, Blackbear, Alessia Cara, Logic, Hozier, Imagine Dragons, Calvin Harris are all pretty high on the popularity scale right now as well. I dunno. Music is hard to recommend for me cause I take music pretty personally.