Here are some suggestions
Buongiorno!
You will certainly need the first two days to explore the wonderful town of Florence and its surroundings. Once you are in San Gimignano, so from the 30th you could consider the following options:
30th of June, San Gimignano:
If you arrive the 30th in the morning, dedicate the afternoon to this really particular, little town that offers a lot.
1st July: One day for Siena (wonderful, medieval town)
2nd July: Monteriggioni, Sovicille, Chiusdino and the gothic Abbey of San Galgano (with the sword in the stone in the nearby Chapel of Montesiepi).
3rd July: The Chianti area (Castellina in Chianti, Radda in Chianti, Gaiole in Chianti and, if you have time, visit the beautiful Sculpture Park in Pievasciata).
Have a wonderful vacation!