モデル作成時にマイグレーションファイルが作成されない

Question

表記の通り、マイグレーションファイルが作成されません。
以下の通りの出力メッセージとなっておりますが、作成方法が悪いのでしょうか。
ご教示いただきたく存じます。

vagrant@vagrant-ubuntu-trusty:~$ cd /vagrant 
vagrant@vagrant-ubuntu-trusty:/vagrant$ rails g model Person 
Usage: 
rails new APP_PATH [options]
Options: 
-r, [--ruby=PATH] # Path to the Ruby binary of your choice 
# Default: /home/vagrant/.rvm/rubies/ruby-2.2.3/bin/ruby 
-m, [--template=TEMPLATE] # Path to some application template (can be a filesystem path or URL) 
[--skip-gemfile], [--no-skip-gemfile] # Don't create a Gemfile 
-B, [--skip-bundle], [--no-skip-bundle] # Don't run bundle install 
-G, [--skip-git], [--no-skip-git] # Skip .gitignore file 
[--skip-keeps], [--no-skip-keeps] # Skip source control .keep files 
-O, [--skip-active-record], [--no-skip-active-record] # Skip Active Record files 
-S, [--skip-sprockets], [--no-skip-sprockets] # Skip Sprockets files 
[--skip-spring], [--no-skip-spring] # Don't install Spring application preloader 
-d, [--database=DATABASE] # Preconfigure for selected database (options: mysql/oracle/postgresql/sqlite3/frontbase/ibm_db/sqlserver/jdbcmysql/jdbcsqlite3/jdbcpostgresql/jdbc) 
# Default: sqlite3 
-j, [--javascript=JAVASCRIPT] # Preconfigure for selected JavaScript library 
# Default: jquery 
-J, [--skip-javascript], [--no-skip-javascript] # Skip JavaScript files 
[--dev], [--no-dev] # Setup the application with Gemfile pointing to your Rails checkout
[--edge], [--no-edge] # Setup the application with Gemfile pointing to Rails repository 
[--skip-turbolinks], [--no-skip-turbolinks] # Skip turbolinks gem 
-T, [--skip-test-unit], [--no-skip-test-unit] # Skip Test::Unit files 
[--rc=RC] # Path to file containing extra configuration options for rails command 
[--no-rc], [--no-no-rc] # Skip loading of extra configuration options from .railsrc file
Runtime options: 
-f, [--force] # Overwrite files that already exist 
-p, [--pretend], [--no-pretend] # Run but do not make any changes 
-q, [--quiet], [--no-quiet] # Suppress status output 
-s, [--skip], [--no-skip] # Skip files that already exist
Rails options: 
-h, [--help], [--no-help] # Show this help message and quit 
-v, [--version], [--no-version] # Show Rails version number and quit
Description: 
The 'rails new' command creates a new Rails application with a default 
directory structure and configuration at the path you specify.
You can specify extra command-line arguments to be used every time 
'rails new' runs in the .railsrc configuration file in your home directory.
Note that the arguments specified in the .railsrc file don't affect the 
defaults values shown above in this help message.
Example: 
rails new ~/Code/Ruby/weblog
This generates a skeletal Rails installation in ~/Code/Ruby/weblog. 
See the README in the newly created application to get going. 
vagrant@vagrant-ubuntu-trusty:/vagrant$ ls 
lesson Vagrantfile 
vagrant@vagrant-ubuntu-trusty:/vagrant$ cd lesson 
vagrant@vagrant-ubuntu-trusty:/vagrant/lesson$ ls 
app config db Gemfile.lock log Rakefile test vendor 
bin config.ru Gemfile lib public README.rdoc tmp 
vagrant@vagrant-ubuntu-trusty:/vagrant/lesson$ cd db/migrate 
-bash: cd: db/migrate: No such file or directory 
vagrant@vagrant-ubuntu-trusty:/vagrant/lesson$

Answer 1

rails new foo
cd foo
```
のようにしてから モデル作成などをしていく必要があります。
(foo 適宜  アプリケーション名(例えば sample などを指定します)

各種の rails の入門記事を参照するとよいです。