Pumping 101? Nursing after pumping at work

FirstTimeMom💁🏻🤰🏻🤱🏻

If I go 4 hours at work without pumping and then nurse as soon as I get home on one side - do I pump the other breast ?

I hadn’t been and now after only being back at work a little I’m noticing lower milk supply. Trying to figure out what I’m doing wrong ☹️

Also any pumping 101 resource you’ve found helpful - I feel so clueless and now I’m nervous and upset I’m screwing up my supply 😔😞