Keep it steady at 80-85 for 18-24 hours. If your culture was active, it will acidify and coagulate. Then drain it in cheesecloth. At the end, you will have a fresh cheese like chevre, which will keep for a few weeks in the fridge, or which you can freeze.
If it did not set and everything else is the same, your rennet is probably off, or you didn't use enough rennet, or you mixed it with chlorinated water. Might be the milk, but less likely.