Laravel – Vagrant: vagrant up command gives “A box must be specified” error

I am getting this error when trying to run the "vagrant up" terminal command:

There are errors in the configuration of this machine. Please fix the following errors and try again:

*A box must be specified.

In my Homestead/.vagrant/machines/default/virtualbox folder, there is no file there, so I'm assuming that is what it's referring to when it says a box must be specified, however I don't know how to include a box as this is my first time using vagrant, and I've searched online with no resolve.

Anyone have a solution to this?

EDIT (Vagrantfile):

require 'json'
require 'yaml'

VAGRANTFILE_API_VERSION = "2"
confDir = $confDir ||= File.expand_path("~/.homestead")

homesteadYamlPath = confDir + "/Homestead.yaml"
homesteadJsonPath = confDir + "/Homestead.json"
afterScriptPath = confDir + "/after.sh"
aliasesPath = confDir + "/aliases"

require File.expand_path(File.dirname(__FILE__) + '/scripts/homestead.rb')

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
    if File.exists? aliasesPath then
        config.vm.provision "file", source: aliasesPath, destination: "~/.bash_aliases"
    end

    if File.exists? homesteadYamlPath then
        Homestead.configure(config, YAML::load(File.read(homesteadYamlPath)))
    elsif File.exists? homesteadJsonPath then
        Homestead.configure(config, JSON.parse(File.read(homesteadJsonPath)))
    end

    if File.exists? afterScriptPath then
        config.vm.provision "shell", path: afterScriptPath
    end
end