Girls, can you tell me how to express breast milk for an inexperienced…

Girls, can you tell me how to express breast milk for an inexperienced mother? I'm breastfeeding and we've never separated from each other. Now I need to go out on errands with my child for a week, leaving him with my husband. I need to pump. Can you please tell me how to give expressed milk in a bottle to the baby? For example, should I put it straight into the refrigerator (for how long)? How do I warm it up? What temperature is right? Or can I skip putting it in the fridge if it was expressed two hours ago before feeding? In general, tell me all the nuances down to the smallest details. Thanks in advance ?