So what is the most recent game in the series that I can start with that is worth it to play and wouldn’t confuse a newcomer?
All of the FF games – baring the ones that are explicitly sequels, like X2 – are totally separate from each other, you can jump in anywhere. At most you might miss some references or easter eggs.
If you want the most recent then, that’d be XVI, although I’d personally recommend looking up what the gameplay is like in the different games and starting wherever you feel you’ll have the most fun! There are some weirder ones out there, like crystal chronicles (my own first final fantasy game) and tactics, so you have a lot of options!