With all due respect, there is a lot to learn. Could I recommend any post by 100model on HMEM. He also has many videos on YouTube and debunks a lot of myths about metal casting, especially cast iron, on which, IMHO he is an expert.
When I first started pouring metal the mantra was vent,vent,vent! What a load of crap. If your sand is right ,this is unnecessary unless it is a really thin casting that has to run a long way. Myths about sand bombs, molten metal flying everywhere unless you vent, bull****. There are a number of books by C.W.Ammen which are invaluable, in your case, "Casting Iron" would be appropriate .Most of the old skills have been lost and are then re invented as new skills. Really, it is not rocket science.