How do I start over.? I had to stop for a time. I want to begin from the very beginning.
You have to reset your progress. Just go to Settings -> Learning Language -> Reset or remove Languages
I don't think you have to start over. I was thinking the same thing also when I didn't practice Spanish for 5 months. All I did was refresh, and it was totally fine. If you start over, then you'll probably have to redo the basics that you already know.
I have started over before. I enjoyed taking the placement test to see what I remembered. :)