Yes, use a new yarn end from a ball of yarn. Hold the end in place as you pick up the first few sts and then continued picking up down the front edge.
The easiest way to decide where to pick up sts is to divide the left front edge into halves or fourths. Then pick up half the sts or a fourth the sts in each section. That helps you space them out approximately evenly. You may not be picking up in every stitch or every other, it may be 3sts for every 4 rows. You'll have to decide how to distribute the sts but don't worry too much about this. As long as they're approximately evenly distributed you'll be fine.
Before you pick up sts for the collar, you join the front and back at the shoulders so that you'll be picking up around a circle as in the video. Once you have picked up all the sts you'll be joining to knit in the round. So you'll start knitting the second round by knitting the sts on the needle that you picked up for the left front edge