Can't set up RSS feeds on wordpress

Hi everyone I’m very new to everything. I have been trying to set up an rss feed using feed burner and get the following error:

The URL does not appear to reference a valid XML file. We encountered the following problem: Error on line 12: The reference to entity “v1” must end with the ‘;’ delimiter.

I have created an XML file with google sitemap. I am not sure what else could be the problem. I also tried to create a feed using the default wordpress widget and also get an error about my website url.

Any help would be greatly appreciated thank you.