Incorporating pumping

Hi! My son is 6 weeks old and I’ve been exclusively breastfeeding until now. I’m looking to incorporate pumping just for convenience purposes. I’m a little confused on the process. I’m going to start by pumping twice a day after feedings. If I feed him and then pump at 10am, and use that pumped milk for his feeding later in the day (let’s say around 3pm), do I have to pump at 3 to keep up supply and/or avoid engorgement? Or can I just skip through that feeding all together? If I have to pump at that time anyway, what’s the point?