如果您要在台上做演讲或表演，您可以使用以下句子来开场：
"Good evening/morning/afternoon, everyone. My name is [Your Name] and I'm here to talk/perform for you today."
"Hello, everyone. It's great to be here with you today. My name is [Your Name] and I'll be sharing/performing for you."
"Hi, everyone. My name is [Your Name] and I'm excited to be here with you today to present/perform."
这些句子都可以用来在台上介绍自己，并向听众表明您将要做什么。在开场时，重要的是要礼貌地向听众问候，并让他们知道您的名字和身份。