I have done yougart, highly recommend a plain variety that is good quality..... yoplait wouldnt be my first choice.
Not sure room temp will cut it. i used a heating pad to keep temps up around 90 degrees for 2-4 days.
I think the biggest part of it is making sure you sanitize ( boil ) the jars, spoon and thermometer, get the milk up to 180ish degrees F, not enough to boil, like on the verge of scalding, i believe this step breaks down something in the milk to to make it easier for the bacteria culture to digest more than it is to sterilize the milk. Then just -make sure- you dont dump the yougart( live culture) in until the milk cools down to around 100-110 degrees F. it will die basically instantly if it is too hot, and wont grow quick enough if it is too cool.
Kraut is a million times easier. cut cabbage, toss it in a bowl with some salt and wait a few hours pressing it occasionally to release the juice, then pack into jars using a un cut cabbage leaf to press the cabbage down under the juice, may need to add some water. put a lid on the jars, stick anywhere that is at least 70 degrees F, burp it daily( could even just leave the lid on loosely) and ensure the cabbage is still under the juice after 3-4 days, taste test, if you like it.... refrigerate to stop fermentation.
Kombucha is super easy too. i hate the drink, but, i love the symbiotic organisms themselves.
i have 3 half gallon mason jar "hotels" with a bunch of SCOBYs. If it is legal to send SCOBYs in the mail i could send a few out if anyone is interested.