Fuel ratios are different for different engines, but ratios of 40:1 or 32:1 are pretty common. This means you put 40 parts of gasoline with one part of oil. In metric measurements, that would be 400cc of gas to 10cc of oil. Mix the correct ratio together in a suitable vessel like a jerry can or bottle. Seal the container, and shake thoroughly. It’s always best to mix your fuel before you put it into your fuel tank, not after.