about 2 months ago - someonesneaky - Direct link
DLC is by no means required.

My suggestion: Try vanilla for a while. Get used to the gameplay and mechanics, you'll have enough to deal with in that Play until you think, 'hey, I wonder if there's a mod that will let me do X'. I can guarantee there will be.

Start with quality of life things, when you get into modding. You don't want to get into something that rewrites something in base game before you know how the base game does things.

The DLC add different things depending on which is your preferred playstyle.

Royalty - adds the Imperial faction. Focuses on faction reputation, quests, psycasting (which is basically magic-but-technology). If you want combat and questing, pick this one.

Ideology - Adds the Ideolegion system, basically beliefs / religions. Focuses on rituals, ideological differences. If you're wanting roleplay, pick this one.

Biotech - Control mechs, play with genetics, have kids. Adds different xenotypes (such as imps - fire-breathing demon-types, yttakin - furries, sanguophages - vampires, et cetera), along with their own factions.

Just picking one is a tough choice, I don't envy you that.