Below are some common tunings for your cigar box guitar. You will need a tuner.
The most common tuning for Cigar Box Guitar is open G: if you check out YouTube, you’ll find numerous examples of cbg’s played in the key of G. Usually these are 3 string, tuned GDG , but sometimes 4 String, tuned GDGB or DGBD. Open G is a really good place to start. Most of Junkbox Guitars are tuned to Open