Watch the The Nieliwocki Stroll online guitar lesson by Brooks Robertson from Essentials: Boom-Chick Fingerstyle Etudes
First watch and listen to the performance video a few times to help become more familiar with the tune, form, phrasing, etc. Try humming the melody without your guitar. Having a sense of the general shape of the melody in your ear will help as you begin learning the piece. There is a lot of syncopation happening and often melody notes will be anticipated before the beat. You'll notice the added wiggle or bend here and there for some added personality. As you watch, focus your attention to what the right hand is doing, then rewind and watch again, this time focusing on what's happening with the left hand. Use this video as a resource to frequently reference and eventually to play along with as well. Don't forget to utilize the tabs, charts, and notation.