iMessage help needed: How do I import contacts from the iCloud onto my MacBook itself?

I am new to the Apple family, so bear with me!

My goal is to sync all of my contacts from iCloud into iMessage so I can send texts from my computer.

I have used every troubleshooting technique that I can find. So far I have activated the iCloud on this MacBook in every setting. When I open the brown Contacts application in the bottom toolbar, all of my contacts appear under "All iCloud." However, the "All On My Mac" section is blank.
1.) How do I transfer my contacts from the iCloud to the storage of my Mac itself, so that they show up in the All On My Mac section?

2.) Will accomplishing this make my contacts appear in iMessage so I can send texts from my MacBook?

Thank you!