I'm scared because price Bitcoin down, I do not know what to do with Bitcoin at this time

Buy a little more.
I am pleased that it pulled back. It will let me continue building my position below $1000.
I expect the price to chop around for several weeks. This is normal behavior for a financial asset.
I expect it to be significantly higher in 2-3 years.
I agree and since it has pulled back below $900 now might be a good time to add more BTC to your holdings. It will most likely bounce around these levels for a while and hopefully next time we break 1k it holds strong above that level so like I said now might be a great buying opportunity to add some more BTC.