Is leagues a good time to first experience the game?

For context I’m a nearly maxed main in osrs, have been playing for about 4 years. I’ve never played RuneScape 3 or even looked into it at all, but the new Leagues has piqued my interest.

I’m wondering if that’s good for a first experience or if I should play the game normally first? I’d plan to play as an Ironman as I do have a low lvl iron on osrs that I love playing when I get bored on the main. I’d also want to go in completely blind and figure out everything myself.