I am exploring if Band in a Box is the answer?
Once again, getting the music set up is the part I want to spend the least amount of time on!
What can I do?
Whoever suggested you look into BIAB was on the money. Outside the approach of downloading karaoke tracks, there is no faster, more flexible, and in my opinion better choice for backup tracks for cover. Karaoke is karaoke. What you see is what you get. BB permits style, mix, instrument changes & the rhythm sections are awesome.
If I see a problem, in your approach, it is in music theory hesitancy, a lack of committment to learning the basics that will, in the long run, I fear cause you some regret and slow you down, ultimately, short of the goal. This could be the reason users here are suggesting commercial backing tracks.
I suggest getting familiar with Chordie.com, which is a vocalists' and rhythm guitarists' lead sheet site -- lyrics and chords.
With any software, user friendly as it may be, there is no getting away from time spent learning the program. If you're not willing to take that time, then the karaoke may fill your need.