Excited + infinitive with "to" Vs excited about

Hi!

I'm having trouble understanding the difference between "to be excited about something" and "to be excited to do something".

- I'm very excited to go back to my home town to meet my family. (Has the action of going back happened, here? Or Is it yet to happen?)

- She said she is excited to return to San Diego. (I have the same confusion here, too. Has she returned or will she return in the future?)

- Sarah was so excited about joining the team. (Had she joined at the time the sentence was uttered or was she going to join afterwards?)