is there any free shuttle bus from Macau airport to senado square or to a hotel near senado square?

No direct shuttle bus. But you can take shuttle bus of Venetian to the resort first. Then walk to the opposite of the street to transfer to the free bus of City of Dreams and get off at Hotel Sintra. Then walk to your destination.

Or take bus no. AP1 to Macao Ferry Terminal. There you can take the free bus of Hotel Sintra or Grand Lisboa to the terminal station. After getting off, walk to your hotel.