You will need to purl on the back, but it's about time you learned how to do Sister Purl!
Use whatever cast on you're comfortable with. It won't matter with this pattern.
When they say to 'increase in the next stitch,' use the knit in front and back method. Amy has video for all the increases and decreases in the pattern.
Just follow it line-by-line and you should be ok; if not, hop in here with your question.