Your phone, like many Android phones has two different ways you can replace the screen. First is the recommended way, which involves replacing the screen and the frame as a single assembly, while the second method is to replace the screen by itself.
The cost difference between buying the screen+frame assembly vs. just the screen is usually only a few dollars, a cost that is usually offset by the need to buy a tube of adhesive glue if you're doing the screen only replacement, so price isn't really a determining factor here.
With the screen+frame method you will essentially gut the phone, removing all of the internal components and moving them to a new screen+frame chassis. If your frame is bent or has cosmetic issues, this method will take care of that with the result that your phone will look like new again. The process is a bit time-consuming but not particularly difficult, and you won't have to worry about sealing the display against liquid ingress since it comes already mounted on the frame. Here's a guide showing you how to do that replacement.
[link|https://www.nadiemellamagallina.com/en/manuales/smartphones-1/vivo-926/vivo-y20s-1291/pantalla-completa-11511|Manuales / Vivo Y20s / Full screen - Nadie Me Llama Gallina]
That video is for the Y20S rather than the Y20, but going through the specifications for the two phones the only difference I could find was that the Y20S comes with more memory.
With the screen only method you have to separate the old display from the frame, clean off the adhesive then glue down the new screen. The procedure is completely different from the other way, so you'll want to go with Harry's search to find a video showing you how to do that.
Good luck, and let us know how it all turns out. I'd be interested in knowing which method you decide on and why you made that choice.