This is me making butter at home. I put only cream in a jar and shook the jar for about 15 minutes and it was supposed get hard, (well not like rock hard, but not runny, so like a paste).
But it didn't go solid so I put a metal cookie cutter and shook the jar for about another 15 minutes and at last it became solid. I put some salt and pepper in and put it on some bread and ate it.
It tasted good and I want to eat it on bread again.
It was quite easy so you should try making it too.