I have an opportunity to buy raw milk and raw cream at the end of the week!
How much should I get and what should I make?!
That's a bit like saying I have two weeks off from work: where should I go?
I would suggest that you get a gallon of milk (if you can) but 3 liters is OK too. Never tried anything with cream. What might you make? That's a tough question.
If you don't have a press or a form you may want to stick with fresh cheese(cottage cheese, for example or ricotta ) . If you have forms and a press then you could aim for something like a Feta cheese. Although it is traditionally made with sheep's milk you can make it with cows' milk and while the addition of an enzyme called Lipase may enhance the flavor similar cheeses from the middle east are often made without added Lipase and they taste better than OK. Another cheese you might try is Halloumi. Neither of these cheeses require a lengthy aging process. If you don't have any of the "classic" cheese making books you might check out Gavin Webber (note the spelling) cheese making videos on Youtube. He's good and seeing what the curds should look like can be very helpful, in my opinion.
But four points: One of the secrets of cheesemaking is to bring the temperature of the cheese up very, very slowly. The most simple method for doing that is to always use a double boiler: that is a smaller pot that is heated using the water held in a larger pot. And the secret to this is to keep the bath about 10 degrees hotter than your target temperature for the milk. Milk is very massy and does not quickly lose temperature once you have heated it to the desired temperature. What I would recommend is that you boil some water in a kettle and use that water to add to the water in the boiler. Bottom line: heating milk for cheese is a labor intensive process.
The second point is that if you can find or have living kefir you do not need to buy different cultures. Kefir has bacteria that reproduce at mid temperatures and at high temperatures and it has a very complex population of many, many different cultures. The idea is that the cultures to make different cheeses live and reproduce at different temperatures. Kefir is a universal culture. I typically add about 1/4 C of kefir to the milk
Third point and it does not really apply to raw milk but if you are using store bought pasteurized milk you want to add a scant 1/2 t of calcium chloride (your LHBS sells Ca Cl). Pasteurization damages some of the calcium in the milk and this restores this mineral.
Fourth point: You want to dissolve any additions (Calcium chloride, lipase, rennet) in non chlorinated water. Chlorine can neutralize the action of rennet.
Good luck!