What kind of congee are you looking to make? Plain or seasoned?
Then ask yourself whether you will be using uncooked rice, or leftover rice.
(All these directions are for the stovetop, even though I know some like to use a rice cooker, slow cooker or pressure cooker, but, really, I think the stovetop method is the best.)
If making plain, using uncooked, then use a ratio of 8:1 (water to rice) or maybe 9:1 if you prefer something a bit less viscous. Add the rice and water to a large enough pot where the water only rises half way, then bring to an immediate hard boil for 30 minutes uncovered. Then turnoff heat, cover, and let it sit until the pot is completely cool to the touch. Congee is ready. (Also, I recommend either distilled or purified water, preferably the former.)
If making plain, using leftover rice, use a ratio of 2:1 (water to rice) and add water and rice to the pot and let it come to a hard boil, then immediately turn down the heat and simmer partially covered until it reaches desired consistency, stirring occasionally. Sort of like risotto, but so much less finicky.
If making seasoned congee, using uncooked, use the same directions as above, but my preferred stock of choice is either turkey or chicken, with a handful of conpoy. Don’t use any other water other than stock.
If making seasoned congee, using leftover, use the same directions as above for leftover rice, and use either turkey or chicken stock. Skip the conpoy. Leftover rice made with congee is best eaten with Chinese pork floss in my opinion.
Enjoy, and get better.