Macbook Air autocorrect spelling and punctuation now working, even with all the correct settings enabled

I am new to Macbooks and have always worked on a windows operating system and for some reason thought this was normal for it to not autocorrect.

Now knowing that it should actually be autocapitalising or autocorrecting my spelling is great, if it worked on my device.

I have ensured that all the settings within the keyboard settings are turned on and when inside my apps, I have checked under the spelling and grammar options and they are all enabled. My device is still not actioning it for me though.

I have had this issue for quite some time, however recently I have started journalling more often using my Macbook air, and having to manually capitalise or add punctuation into my entries would save me time and allow me to continue my thoughts without having to go back and correct and fix the entry.

Thoughts?