FTM who has no clue what I’m doing .!😫

My son is lil less then 5 days old and I’m a FTM all this is new to me . I notice engorgement 2 days ago and haven’t felt the relief of not being full anymore. Is that how it suppose to be .? Could he not be feeding long enough .? . I’ve been feeding him every 1 1/2 to 2 hours or when he shows signs of wanting to eat BUThe is only staying on for 6-10 mins from one breast (alternating after each feed) I thought I read feeding takes 20-40 mins🤷🏽‍♀️. How long should a newborn feed .? Should he be going on both breast durning a feed .? And any tips on how to keep him awake during a feed ? I’ve tried undressing him , changing diaper, rubbing him not sure what else to do to keep him interested in feeding and not falling asleep . He has his first doctor appointment tomorrow and I’m worried they will tell me he hasn’t gain . He lost 5% of his birth weight when we left the hospital. (Nurse told me that was good and shows he is not starving ).and any tips on getting through engorgement .???

Sorry for ALL the questions .! All the other moms I know formula feed.