Install everything via Brew.
This will check for, and install, Xcode CLI tools and Homebrew before executing the Brewfile.
./install.sh
Ensure xcode is installed.
xcode-select --install
Ensure Homebrew is installed.
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
Finally, use Brew Bundle to install all formulas, casks, VScode extensions, and App Store purchases.
brew bundle --file ./Brewfile