After fork and clone you have to run bundle install then rails db:create before starting the server.
Steps to setup Devise: Paste this in your Gimfile
gem 'devise'
Then run
bundle install
Then run
rails generate devise:install
Paste this configuration inside config/environments/development.rb:
config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }
Then run
rails generate devise User
Then run
rails db:migrate