BITCOIN HELP

I've been contacted to move to bitcoin. Could someone please answer; how do I turn it back to cash?

Can't seem to get a straight, simple, or logical answer.  Trying to understand.

If anyone knows, I would greatly appreciate it.

Thanks, in advance

HS

Yes thank you but the process. Sell it to whom?

The value bought 10, dropped to 9, now it's 20 - I want to sell it at 20 but who is buying it

and how do I convert it to USD (@20)?