1.We'd like to talk to you about taking over his contract. 我们想和你谈谈关于他的合同的事情
would like to”愿意,想要,准备“;
I would like to commend him to my friends.
我愿意把他推荐给我的朋友们。
I would like to go to an inexpensive restaurant.
我想去花费不大的餐厅 。
2.Since...you should..”既然...那么你应该...“,这是英语中常用的表示因果关系的说法,since是”既然“;
Since you don't answer the question, you should ask someone else.
既然你不知道这个问题的答案,那你该去问问别人;
Since today is very fine, I think we should go out for a walking.
今天天气不错,我想我们可以出去走走。