The base game of Destiny 2, now known as Destiny New Light is a free downloadable game from steam, ps4, or Xbox 1. In this version it contains content from The Red War, Curse of Osirus, and Warmind with all unlocks to the newer areas that arent part of the base game campaign. It also contains the Annual Pass content from Season of Forge (Black Armory), Season of the Drifter, and Season of Opulence not including the Exotics and Raids from the Annual Pass except from the ones listed with the Destiny logo. You'd be able to access the same level as other players that spends money to continue with the Destiny story so then if you already love playing Destiny but can't buy the expansions you'll still be able to catch up without it.