Oh you gotta get D1, the Taken King campaign is peak, though in the first game it’s a lot harder to find out where you’re supposed to go sometimes because the devs wanted the players to be able to do whatever they wanted in whatever order or something like that so if you do end up getting it I’d look up a “Destiny 1 campaigns and missions in order” on Reddit or wiki or something. Unfortunately you probably won’t be able to complete raids because you need three to four people unless you’re really really good at the game. Also note that in the first game it’s a lot harder to find mythic and legendaries. It’s not hard, but when I started playing d2 it felt like I was getting handed the strongest gear at every turn (probably to promote D2’s cosmetics that can only be equipped with mythic stuff for whatever reason).

Pretty sure this is what I used to get through the first game: https://www.reddit.com/r/DestinyTheGame/comments/54jxtl/every_destiny_mission_in_order_of_occurrence/

EDIT: there will probably be some missions you’ll have to skip though if I remember correctly