I’m a new knitter, I’ve been doing great on a mitten pattern, but after I divided for thumb by slipping stitches on a holder, it said to cast on 2 stitches next to the first knit stitch that I did before slipping the stitches on a holder. How do I cast these 2 on? I’m not sure if it means starting a new pc of yarn or continuing with the one I’ve been using. Help! Any known video of this? I don’t know how often this would be used, but you never know!