It make me delighted that you show great interest in ...and that you want to know something about...
这是一个主从复合句,it 是形式主语,它代替后面的that you show great interest in... and that you want to know something about...。谓语应是makes,不是make。宾语 me 。delighted 是宾语补足语。
and连接了两个并列的主语从句,作本句的真正主语。