Colon cancer

I have just been diagnosed with colon cancer , i have to have more tests but it is a large tumour 5cm i feel fine very worried but i don't feel ill at all if it hadn’t been for small amounts of blood and mucus and two small blood clots i might never have known i had it and just carrying on as normal , does anyone know what happens next  ? I have to have a CT scan then possibly surgery at some point , what is the timeline for this ?