Bitcoin Armory is a very old wallet that hasn't been updated for a long time now (about 2 years as far as I know). You shouldn't use it for any reason.
Wow. You living in 2019?
blockchain.info.
Alright, ,maybe you have no idea what you are doing. Its notorious for being unreliable.
Armory runs on a Bitcoin Core as its backbone. You have to download Bitcoin Core first. I would really recommend something other than Armory, its a bit of a hassle for most users.
Tutorial is here:
https://www.bitcoinarmory.com/tutorials/armory-basics/. Let me know if you need any help.