Running multiple apps

Sorry for the newbie question.

Anyway, so I set up Rails on a subdomain. I generated a new app in
there, and everything works fine. However, I went to another tutorial,
and the tutorial said to create a new app. I did, in the subdomain, but
now this leads to me having a subdirectory (the name of the new app)
with all the generated folders gathered with the generated folders from
the first app. I thought I could work it by just going to
subdomain.domain.com/second_app, but I can’t because it gives me the ‘no
route found to match “/second_app” with {:method=>:get}’ error.

So should I just run everything off the first app? But isn’t that
against the point of Rails keeping everything organized? What happens
when someone wants to run multiple Rails apps off the same domain? I’m
actually doing this off of a shared hosting account, so I can’t touch
anything like the server config.

Thanks for any help!