Dictation software for MacBook OS Mohave and microphone I am a writer

It's built into Mac OS.

Use your voice to enter text on your Mac - Apple Support

I suggest using a USB microphone rather than the built-in mic. This will reduce ambient noise.

So I don't have to jump through flaming hoops to decode A1534, why not share the parenthetical model year from menu : About This Mac?

The best dictation software used to be Nuance's Dragon Dictate for the Mac, but they have ended Mac development and the party is still going on with Windows 10.

Apple includes Dictation in Mojave that will use your MacBook's built-in microphone, and send your spoken words to your document, whether that is Pages, Word, or even Scrivener 3.1.2. There are two modes:

1. Ordinary dictation
   1. Your spoken words are round-tripped to Apple servers, interpreted, and sent back into the current document. Most accurate, but can be slow based on network health. Apple will continue to tweak the dictation servers' ability.
2. Enhanced dictation
   1. All spoken interpretation occurs local to your Mac. Additional download to effect local processing, with more punctual results, though may be less accurate than the ordinary dictation choice.

Which ever you choose, dictation will progressively learn about your speech patterns (so you will cuss less) for improved dictation results.

Here is some information to get started:

1. Use your voice to enter text on your Mac
2. Use Dictation Commands to tell your Mac what to do

When you first launch Dictation, wait until the three pulsating globes stop, and a microphone avatar appears. I continue to use the fn fn sequence to launch Dictation. The first thing you should do after the Dictation avatar appears is to say, Show Commands. This will pop up a panel with various expressions that you can use.