To speak more fluently, you need to do two main things:
1. Listen a lot to native audio of natural situations -- TV shows or Youtube videos in which normal people interact in daily life, for example.
2. Imitate native speakers. Listen to a sentence, and then repeat it several times. There is a technique called "shadowing" that I find very useful. Record yourself and play it back. Notice where you have problems and concentrate on fixing them. If you don't sound right and you cannot figure out what you are doing wrong, get help from a professional on how to shape your mouth and where to put your tongue and how to breathe so you can produce the same sounds as a native.
Speak out loud. Talk to yourself in your new language, as much as possible. Your inner voice is not the same, and it is not good enough to only say things in your mind. Describe the world around you in the new language, every common thing. You will develop more vocabulary, better sound, and greater fluency the more you do this. Practice, practice, practice.
After you have done that a lot, start speaking with native speakers so you learn to think on your feet, and respond appropriately in conversation. Record those sessions and play them back to analyze what you need to improve.