Tips for a CHA/DEX based martial build?

Just started the game, want to do a kinda classical swashbuckler type with Weapon Finesse and high CHA, open to some casting but don't want that to be the core of the build. Took Scaled Fist at first level to get CHA to my AC, was also looking at Eldritch Scion or Paladin somewhere down the road.

Any good Rogue subclasses I should try and dip a few levels into? Good ways to get CHA (or Dex) added to Damage or Initiative or anything else fun? Anything particularly fun or flavorful for the kind of Errol Flynn archetype I'm shooting for?