Get every chance to speak, whatever the situation, so you will improve your fluency. Listen to story books and read with the speaker simultaneously, so you will learn the accent.

I would say practice speaking every chance you get (preferably with a native speaker, which can correct the way you say things). You will get used to hearing and producing the sounds as well as get accustomed to making correct grammatical structures. All the while, you will be producing sentences more and more quickly (i.e. more or less automatically.)

Practise. Relax. Get the sounds right.

Study for many, many years.