“首先，请允许我自我介绍一下”这句话用英语怎么说？

“首先，请允许我自我介绍一下”
Fist of all, Please allow me to introduce myself.

If you want to sound more American, you could say "Firstly, I would like to introduce myself."
A lot of times, when people try to translate from Chinese directly into English, it might sound really awkward due to the differences in culture.
It will sound a little bit demanding if you use "Please allow".
Because when you start a conversation, "introduction" is your own preference rather then a permission from others.
Good luck, buddy! : )

First, please allow me to introduce myself.

Hi everyone
At first, please allow me to introduce myself