Help me with Java project. Involves making RSS aggregator and building from seed code (not that hard)

Most of all, I don’t understand how to do it. So if you could explain some things to me that would be perfect!!!
So you will follow the instructions in “project 5 instructions” and use “my project 4 code” as reference when it asks you to copy and build from your “previous project”. My project 4 DID work though! I just dont know how to make project 5 work.
Some questions I already have are :
1. How do I test to see if my code works? What kind of URL do I type in? How do I know if an URL has a RSS XML 2.0 feed?
2. Whats an XML RSS feed?
***It is now 3:40p on 10/8/21 for me. I need this by 8am on 10/10/21***But I really want it ASAP! So if you have extra time then can you work on this?