首先；其次；再次；最后 我们只会说老掉牙的 first（firstly）；second （secondly）；third （thirdly）；finally

其实还有很多种替代讲法

首先：to kick off; to start off; to begin with; the very beginning

其次：in addition to that; apart from that; aside from that; besides; also; another point i could add is; and....as well; what's more; further more

再次：one more thing

最后：my point of view is; let us draw a conclusion; to sum up;