Someone said my iCloud account has been hacked and is trying to get all my data

That is called a phishing attempt. For tips identifying those and reporting them, review this Support Article. It happens all the time, sometimes from people claiming to be your bank looking for financial information.

Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

After restoring your phone using the information provided by IdrisSeabright, make sure you also change your Apple ID Password.

Update your Apple ID password - Apple Support

Never call a number provided to you from an email, message, or from a popup while browsing the web. Using Google to search for numbers is also problematic since scammers pay Google to appear higher in their search results. The only way to get a number for a company is to navigate to their official company webpage and do not do that by clicking a link in an email/message.

elyse285 wrote:

I called this number 844-***-****which I thought was Apple support to help me because I was locked out of my iPad. They told me my iCloud account was hacked and then accessed my phone remotely

Restore your phone to factory settings. If you have a back up from before this incident, you can restore that. If you don't have one from before that, do not use a backup.

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

Who is this someone?

If you think your Apple ID has been compromised - Apple Support