Take your ammonia and nitrite and add them together. If the combined total is higher than 0.5ppm change water until it's below that 0.5ppm target.
Looking at your test results, ammonia is about 0.25ppm and nitrite is about 1ppm. Together they are 1.25ppm. A 50% water change would halve these parameters and bring them to just above 0.5ppm so a couple of 50% water changes would be in order.
Your cycle is a dynamic thing, there is no such thing as it being "finished". The microbes responsible for your cycle grow or die off depending on how much ammonia is present. You will be cycled sufficiently for the number of fish you currently have when your ammonia and nitrite tests are consistently showing zero. If you then add more fish your cycle would need to catch up to the increased bioload, and ammonia + nitrite might again start to show up in your testing. If fish die off, so will the microbes, and your cycle would adjust to a lower bioload. Subsequently adding back the numbers of fish you currently have would again mean your cycle needed to catch up.
