$20.00 2017 Star Note

There is a tool you can you to lookup a star note here:
https://www.mycurrencycollection.co.../NE04561540*

or buy a book like Paper Money of the United States which covers all things currency and has the general values for star notes.
https://www.amazon.com/Paper-Money-.../0871845229/

So this note is not really worth anything over face value currently. Some people like to keep uncirculated star notes even when they are not 'rare' and someday the values may go up (as this is a recent 2017 note). You can also always check ebay sold listings (not what is currently listed but may never sell for the asking price) to see what current values are as they will sometimes be very different from the guides and can help gauge any demand for something. Its possible for something to sell even when not rare here and there.

It's from a huge run of 6.4M notes printed in February 2019. Most modern star note collectors prefer uncirculated examples, especially on higher denominations.