Breathing in and breathing out is Anapanasati meditation. It's a Samatha(tranquility) meditation as "breath going in and out" is a concept. If you want to practice Vipassana, you must note the sensation at where the air hits in the nose. That is usually subtle compared to the movement of the abdomen. Follow this booklet. You can also signup for the remote meditation course. It's better to practice under a qualified teacher rather than doing it on your own and trying to get guidance on the Q&A site.