Learning the alternating thumb roll and the forward/backwards rolls is a great way to start playing 3-finger style banjo. Always play slowly in the beginning, and focus on good technique and timing.
Start by strumming chords to learn how to switch fluidly between each one. Then add the roll patterns you learned in "Beginner Rolls." Once again, slow practice is essential to ensure you're solidifying the correct technique and timing.
Two very common techniques in bluegrass banjo are pinches and slurs. Use this lesson to practice the correct timing, and then you'll be well on your way to learning your first song - "Cripple Creek!"