Always start off low flow and low light area. Mushrooms can always be adapted to higher flow and par but it needs to be done slowly and over a long period of time. I’m talking months and months.
I wouldn’t worry about directly feeding mushrooms. Although it can be done, I find it that more often than not, more harm is done to the tank than good. A lot of the food directed at the mushroom tends to go to waste and just pollute your water. Just make sure your fish are fat and you’re water is changed bi-weekly and that shroom will explode in no time