Litmus paper can only be used to determine whether a solution is acidic or alkaline. You are confusing it with urine dipsticks/test strips that measure glucose.
I should point out that a person with normal kidney function would only excrete glucose in their urine if their blood glucose level were well above the normal range. Most healthy people have no glucose in their urine.
If you suspect you may be diabetic, you should seek medical advice rather than attempt to self diagnose with dipsticks. And if you want to test your blood glucose level, you need to test your blood. You can buy glucose meters in most pharmacies.