Welcome J, i had the same problem as you trying to play this song plucking both strings together at first, but fret not ;-), it's well worth the effort to make it sound like the iconic Richie Blackmore riff.

The next two parts after the intro (verse and chorus) are pretty easy and that's half the song. In fact Dave just covered Smoke in our group classes in June, helping a couple students get the solo to play the song through completion (my first not counting Breaking the Law which has no solo).

Glad to see you're enjoying this wonderful community as I am,

-Jamie