Procedure to install/try Cosmos - newbie questions

Hi all,
I am completely new to Cosmos ecosystem. Previously I have developed a very simple blockchain by using node.js for research purpose.
Now I would like to explore Cosmos-Tendermint.
I have understand that they are considered two different layers, so both are necessary for the deployment.

My first question is:

  • Do I have to install Tendermint first?
    I have tried the Cosmos tutorial, but it seems to skip some steps. There is a detailed installation guide?
    For example I have an error during the ‘make install’, also executing it as super user:

make: execvp: go: Permission denied
Makefile:18: recipe for target ‘install’ failed
make: *** [install] Error 127

The last question is more conceptual. I have understood that Cosmos is used to build a network of blockchain. Can I have more application examples, please?

Thanks for your support