Welcome to the forum, Eric.
If you want to shoot the rifle, you will need a long cleaning rod at least 4' with a jag that will allow you to use
a small square of maroon Scotch Brite 'cloth'. Spray it with WD40, or some very light oil, and make about 40 full
length passes down and up the bore. You may have to change the cloth square a time or two. This will follow
the rifling if snug, and will help smooth up things a bit.
As it is, this barrel will foul badly and be difficult to load.