It's one of the hardest things to explain to people who have never played a ttrpg, which is that the character you want to play should fit the setting and vibe, which is why session 0 exists.
If you're playing a Dark Heresy campaign and you wanna play a chaos marine, don't get mad if the DM says no
Ela Bambust 🏳️⚧️ (alleged transsexual)
Okay, this is a joke post, but the serious post is: You need a character concept that engages with the plot
"guy who runs an inn" does not engage with hunting dragons.
"normal superspy who hates novas" does not engage with novas doing superhero shit
Dragon Cobolt
Invariably if you make a TTRPG setting about being a thing, someone will ask “oh can I be literally anything else”
Dnd players who want to role play tavern owners, aberrant players who want to play baselines, eclipse phase players who want to play Jovians