我实在不是一个能说会道的人。翻译成英文

口语的话可以说：I'm more like a silent person. 或者 Talking is really not my mark. 或者I don't have the gift of gab.
正式一些可以用：I really don't have a good tongue.

i am totally not a good talker.

I really was not an articulate person.

indeed, I'm not a talktive person.