Cachaça is a Brazilian liquor made from fermented sugarcane juice. If you can’t find it, use vodka, and then your drink should be called Caipiroska.
To make the original Brazilian Caipirinha, replace the strawberries with half of a lime (unpeeled), cut into 4 pieces.
If you don’t have a muddler, use a wooden spoon to mash the fruit and sugar.
For a low-sugar, low-calorie drink, substitute artificial sweetener for the sugar (adjust quantity to taste).