A jam jar
Dried yeast (i guess fresh yeast would do)
Put about a teaspoonful of dried yeast in the jam jar.
Add water, to fill the jam jar about 3/4 full.
Add a teaspoonful of sugar.
Add about 2 tsp ground ginger.
Let the mixture stand at room temperature. After a short while it will send up a lot of froth.
If that happens you are all set. If it doesn't, well, probably the stuff is dead, and you need to get some better yeast.
Feed your plant daily in accordance with the instructions for the ginger beer (in another post).