Muy first day

Hi! Today is muy first day here. I want to improve my English because I need for my job.
I want to practice every day the speaking because I am very nervous when I speak and never want to do.

My first day
Hi! Today is my first day here. I want to improve my English because I need it [English] for my job.
I want to practise* speaking every day because I am very nervous when I speak, and never want to do so.**

* practise [verb], practice [noun]

** you could say something like 'speaking makes me very nervous and I try to avoid it'

I sympathise as I also feel uncomfortable speaking.  We just have to try to get over our inhibitions.