When purchasing coffee you should pay attention to the following
Roasting: You like your coffee strong medium or light
What type of coffee do you like Espresso - Black - Turkish .... .
What flavour do you like your coffee sweet sour acidic nutty vanilla chocolate... .
How do you like to brew a cup of coffee pay attention to the tool your using as every tool will produce different results V60 - AeroPress .... .
Very important is the roasting date make sure that the date is no more than 3 months as the coffee will start to lose its flavour