Here are the steps to turn off autocorrect on your Samsung phone:
1. From the home screen, tap Apps > Settings.
2. Scroll down to the System section, then tap Language and input.
3. Tap Default > Auto Replace. "Default" may be named something else if you have a third-party keyboard app installed.
4. Tap either the green tick box next to your language choice or the green toggle to the top right of your screen to turn off autocorrect .