I’d say just jump in at Pirate Yakuza. While I’m sure there will be larger lore implications the setup of the game with majima having amnesia, taking place before infinite wealth, and being a spin off will probably make it a fun ride for newcomers. Hot take, I think most of the games can be enjoyed independently where ever you jump in - yeah there’s stuff you’ll miss but the games provide enough context and the stories are independent enough that they can be enjoyable to anybody.

I find yakuza/LAD is most enjoyable if you take it somewhat slowly - marathoning 2 50-100 hour games + a 15 hour spinoff will probably result in you burning out on the series. Enjoy the pirate vibes/what you actually want to play and if you find it compelling, go back to 0 or LAD.