I am a fan of Spacemacs, and whenever I have to install it on a new computer, I have to go to the documentation and scroll for a while. This is why I created this quick guide with all the steps I usually follow.

1. Install Emacs

As Spacemacs is based in emacs, we need to install it first. As we're using macOS, the recommended way of doing this is using the brew cask:

brew cask install emacs 

2. Install Source Code Pro font

This is the font suggested for the editor, and we can do it by using the cask/fonts tap from homebrew

brew tap homebrew/cask-fonts 
brew cask install font-source-code-pro

3. Clone the Spacemacs Project

Clone the Spacemacs project, it doesn't matter where, we're going to delete it at the end (after copying it).

git clone https://github.com/syl20bnr/spacemacs

4. Checkout develop branch

As the main or master branch is a little outdated, I always use the develop branch for a better experience.

So let's get into the folder

cd spacemacs

And then change the branch that we're going to copy

git checkout develop 
# Just to make sure everything is updated
git pull origin develop

5. Copy spacemacs

We need to copy the Spacemacs folder into the ~/.emacs.d. For this, we need to get outside the Spacemacs folder and execute

cp -a spacemacs ~/.emacs.d

6. Giving permissions

As MacOS Catalina has new security features, we need to give *Full Disk Access* to the /usr/bin/ruby script which is the one that launches Spacemacs.

For this, go to System Preferences, and then into Security and Privacy.

Then, go into Privacy -> Full Disk Access, and then unlock the lock to enable changes. After that, go and click the add button.

Then you need to search for the /usr/bin/ruby script. The easiest way to do this is with the KeyBoard shortcut

SHIFT + CMD + G  

Which will open a search window and then there we can type /usr/bin/ruby.

We can click accept and lock again to prevent further changes.

7. Verify the access

If you open Spacemacs and the hit

SPC f f 

you should be able to go now to the desktop and any folder you want.

If this is useful for you, please consider giving it a like.
Happy hacking!