Can I replace the shattered screen myself

HP makes their service and maintenance manuals available to the public. Here's the link to yours.

Maintenance and Service Guide HP ENVY x360 Convertible PC

Their manual only shows how to replace the entire display assembly and doesn't go into detail about removing the LCD from the lid and replacing it by itself. You may be able to find something on YouTube, as that's a popular place to post laptop repair videos. The display replacement section starts at page 51; you'll have to ignore the bad link that says it starts at page 36.