How many liters are contained in a cube with each edge 1m?

HOW do you do this?

How do I know how many liters fits into a meter?

generally, one litre of water will fit into a container 10 cm by 10 cm by 10 cm.

or 1 cubic metre is (100 cm) = 1,000,000 cm^3

since 1 L = 1000 cm^3, divide
1,000,000 by 1000 to get 1000

so there are 1000 litres in a cubic metre.

(your last line makes no sense, litres do not fit into metres)