rdr2 question

Finally bought this on the steam sale, playing on steamdeck. Im all about open world games where you can do whatever you want. I hate being locked into "missions", escort quests, etc. I like a game having these as an option to do at my leisure however. Im several hours in and the environment looks amazing, would love to go explore it....... Am I still in an extended tutorial and the game cuts me loose to do what I please at some point or is the game just a series of missions forever? Also is there some sort of open world mode outside of story mode. Thank you, i love each and every one of you.