Go here: https://gorails.com/setup, choose your OS's version and following instructions to install Ruby, Rails and MySQL.
Download source code and open terminal inside it:
$ cd it3_jungle_boys
First, in config folder rename database.yml.example to database.yml, secrets.yml.example to secrets.yml:
$ mv config/database.yml.example config/database.yml
$ mv config/secrets.yml.example config/secrets.yml
Then install library:
$ bundle install
Update MySQL's username, password to file database.yml (line 16, 17)
Create database:
$ rails db:create
Create tables using migration:
$ rails db:migrate
Seed some data to database:
$ rails db:seed
Finally, run rails server:
$ rails server
Open browser and go to address: "localhost:3000"
Hope you enjoy it!