As a die hard one piece fan I can without a doubt say its is extremely long but thats only if you count it by episodes. Regardless its still worth the watch as it will have you going through every emotion you've ever experienced. No lie lol cant count how many times Ive cried, laughed, and got outright mad watching it.
Outside of One Piece(which I highly recommend) I would say watch Black Clover, Overlord, That Time I Got Reincarnated as a Slime, Mashle, Undead Unluck, Demon Slayer, and last but not least Jujutsu Kaisen.
I can go on and on as I live and breath anime lol best thing to distract you from the world and its wickedness but those would be my top recommendations. If you or anybody want more Id be happy to share I watch all genres from the bloody gory animes to the romantic and outright wholesome animes.
OH YEAA A must watch for everyone is Kotaro Lives Alone. Straight brung me to tears