How does it work?

Arduino Uno
Do I need a shield or to be plugged into a computer? I want to run my arduino off a USB power pack and am wondering if I can still use Blynk. I just got the app, so sorry if I should know the answer.

You can connect over USB, but it’s not very easy for beginners and it involves software developed by other guys. Blynk initially was designed for a wireless connections, for the Internet of Things.

You can follow instructions here:

If you have any issues with that - please write here, we’ll try to help. Also, search the forum for trouble shooting

Thanks, I will run it wireless

In the library there are examples for many types of supported shields. Choose the one you have.