Hi, Mr Leo. Senado Square and St Paul Ruins are located next to each other. You can take bus 10 from Macau Marine Ferry Terminal to 新馬路Avenida de Almeida Ribeiro, then get to the square first. You can also take the free shuttle bus to Lisboa Hotel. 10-15 minutes's walk later, you will find the square and ruins. Take bus 10 at Avenida de Almeida Ribeiro, you will reach Ama Temple. Bus 18 can take you from Ama Temple to Macau Tower. Then take bus 21 from Macau Tower to Venetain.