Error connecting to Redis on localhost:6379

I am a beginner for app development.
When I first clone the Jumpstart from the GitLab and tried to launch my app, I faced to the error message "Error connecting to Redis on localhost:6379 (Errno::ECONNREFUSED) (Redis::CannotConnectError)"

After I googled for some hours, it seems that I need to configure some part to set the localhost to be connected to localhost:6379. But I don't know where (which file) and how. Could you kindly advise me how to solve the issue?

double-checking that you have completed the installation steps here, https://jumpstartrails.com/docs/installation. Seems like you don't have Redis installed or that it is not started. Are you running with foreman to start your servers or just rails s?

Thank you. I followed the instruction of the installation. So I think those gems are included. Let me double-check them.
I do just "rails s". (Is it what supposed to do?)

Rails s will start your rails server but if you haven’t run the commands in brew to auto start your redis server than it won’t be running and therefore cannot connect. Here is a gist taking about redis commands with brew. https://gist.github.com/tomysmile/1b8a321e7c58499ef9f9441b2faa0aa8

Thank you. It works now.