It's not going to be possible to knit a 'simple' cardigan in the round. When you knit a sweater in the round, it's all one piece, all the way around. To make a cardigan truly in the round, you need extra 'steek' stitches which you would cut later. Not a good project for a first sweater.
You can make a cardigan where the back and two sides are knit as one piece to avoid seaming and then split for the sleeves.