From the Wiki
1 - Open the archive and drag the Sonarr icon to your Application folder.
Open Sonarr from your application folder
2 - https://github.com/Sonarr/Sonarr/wiki/Autostart-on-OS-X
involves making a plist and such.
If using option 1 can’t I just add it to my login startup items?
Is one better than the other? Right now I am using option 2