Greece is delicious in Sept, fewer crowds, water is still warm for swimming – just avoid Athens this year, because of the fires. Mykonos and Santorini, Corfu are good bets.
Rome and the Amalfi Coast, or the South of France would be good options in Europe, too.
Hawaii (if you want to be closer to home) is less crowded this time of year, too. Maui and the Big Island good for all of the activities and nightlife in addition to the beaches. Kauai is quieter, more romantic and rainier this time of year.
Have fun!- off season travel is the best.
Tips for Venice:
1. Try to get lost. You’re on a small island. When you want to return to your hotel, follow the omnipresent signs leading to the Piazza or Rialto, and go from there. Or find the nearest vaporetto dock & ride back to your hotel.
2. Museums – Accademia, Peggy Guggenheim (modern art), Ca Rezzonico (17th century venice), Doge’s Palace (including the prison & Bridge of Sighs), St. Mark’s Cathedral, Frari church.
3. Best hotels are the Cipriani & Gritti Palace, if you have bucks to spend.
3. Gondola rides are horribly overpriced. Singing is extra.
4. Buy a vaporetto pass as soon as you get to Venice. This will enable you to ride the water buses as much as you like, which is great after a long walk. Plus a vaporetto ride down the Grand Canal is a great introduction to Venice.
5. Don’t neglect the neighboring islands of Burano and Murano.
6. Souvenirs – masks, glass art, verdute (antique prints), marbled paper.