I tried to build a ruby-based website. but I want to start on blogspot which is free for beginners. can the ruby system be placed on blogspot, I am very happy if this happens.
No Blogspot does not support ruby on rails. Even it is just a blogging platform where you already have CMS to serve you. But you should have a development environment. Please try Heroku.com if you want free. check this tutorial https://devcenter.heroku.com/articles/getting-started-with-rails5 to launch your first application on Heroku.
You can add the following lines after
rails generate controller welcome
rails generate scaffold product name 'price:decimal{7,2}'
rails db:migrate
This will create a sample application where you can do all CRUD operation on product. you can try following
rails s
Now visit localhost:3000/products
After installation on Heroku you will get your url where you can run app and do all CRUD operation. Just try it is very easy to do.