To make yoghurt you may either use raw or pasteurised milk. It is unnecessary to heat pasteurised milk, after all it has already been heated. Among the milk you will need either a start yoghurt or some yoghurt culture, that is for example availabe in form of a powder. Some also add milk protein powder, but personally I do not recommend this because it has an aftertaste. It supposed to make the yoghurt a little more creamy, but I think it is still not worth it. You may prepare the yoghurt right away from the raw milk that is heated to 48°C and the just proceed as written in the recipe below. However in that case you should consume the yoghurt witing 3-4 days and the resulted yoghurt will be more sour and less creamy, then when heated to 90-95°C. In case you ferment the bacterias for too long you'll likely end up with a too sour yoghurt. If the yoghurt is too liquid then probably it has been either fermented over too low or too high temperature (above 50°C). Or you have moved it too often and sudden while transfering it to the fridge. So be patient while the fermentation time and do not even think about touching it. I understand that you are curios and want to so if something happens at all, but be patient! I know what I am talking about...!
Heat 1 liter raw milk to 90-95°C and keep it on this temperature for 5 minutes, then chill down to 48°C in a cold water bath. Now add a knife point yoghurt culture powder or a teaspoon yoghurt. Mix it well together and prepare the yoghurt glasses and fill with the prepared milk. Put glasses into a waterbath that has a temperature of 42-43°C and let it stand there for 4-6 hours and take care that the temperature doesn't fall under 40°C. The result is going to be a kind of coarse-grained yoghurt with a little whey. The whey can be drained. In case you desire a yoghurt that is smoother with fine grains you have to keep the mixture for 18-20 hours in water bath that is 30-35°C warm. But I think it is a lot more difficult to make at home, unless you own a machine.
Fresh cheese is made by curdling milk with an enzyme and then draining off the whey. Some fresh cheeses are curdled only by acidity, but most cheeses also use rennet. Fresh cheeses tned to be bland so it is nice to experiment with herbs and spices. My favourite is the túró (a type of curd) or quark, but the Hungarian type is a lot drier then for example the German. At home it is usually prepared from curdled milk that is heated to 60°C and then it is drained.
Heat 2 liters of raw milk, while whisking once in a while to 70°C, then let it cool in a water bath to 20-28°C. Then add 2 tablespoons of yoghurt and a drop of rennet. Now let it stand for 12-24 hours on room temperature. Then either with a knife or a cake decorating spatula cut the curd in 2 centimeters thick slices and let is stand for an hour. A layer of whey is going to appear on top. Now pour it carefully into a cheesecloth covered sieve and let it drain for 6 hours (or maximum 12 hours). By the way instead of the yoghurt you may use buttermilk or kefir. When the cheese is ready pimp it with spices or herbs anything you desire.
The next fresh cheese is a type that you can cut with a knife and it has also spent some time in salty water. You will need both culture and rennet to make it.
Heat 3 liters of raw milk to 65°C, then let it cool in a cold water bath to 34°C. Then stir in a knife point culture (MA4001) and let it ferment for 30 minutes. Then check the temperature, it should be at least 30°C, but better if it is 32°C. If neccessary then reheat it carefully. Stir in 3 drops of rennet and let it stand for another 30 minutes. It is important to keep the temperature constant otherwise it will take longer until the curd reaches the right consistency. It is just right when you put your finger into the curd and when removing it breakes and there no leftover curd on your finger. Then with a knife or a cake decorating spatula cut in 1-2 centimeteres cube. Let it stand for 10 minutes, until a layer of whey sets on the top. Remove 300 ml of whey and add the same amount of 50°C warm water. Now the curd has been washed. Let it stand for 7 minutes and now transefer it into forms. This can be special cheese form or plastic yoghurt forms that you have made holes into it so that the whey can drain. Let it drain for 18 hours while turning it first after 1 hour, then after 3 hours and then after 6 hours again. Now the fresh cheese is ready to eat but you can leave it in salty water for a while. For that cook 1 liter of water with 200 g salt, let it cool and put the fresh cheese in there for 5-10 minutes, or as long you like. But be careful because it can get too salty pretty fast!
And finally, my favourite, that is also a fresh cheese but a lot more creamy then the once before. It has a slight, but really very slight sweet touch and it tastes pretty much like crème fraîche.
Heat 1 liter raw milk to 70°C, then cool down to 25-30°C. Stir in 2 tablespoons of yoghurt and 3 drops of rennet and stir well. Let it stand on room temperature for 6-18 hours. Now cut it in 2 cm slices with a knife or a cake decorating spatula and let it stand for an hour. Now carefully transfer it into a cheescloth and let it drain for 7 hours. Then transfer it into a plastic form with holes and salt the top of it. Turn it the next day and salt it again. In case it has been drained very well, then you can also put it into oil with herbs and spices.