First, I think you need to start with the quality of the bean you bought. I have noticed both at Sam's Club and Costco that more often than not, the bags of beans are not sealed. You need to dig to find a bag where the beans don't slide around inside the bag. If you can shake the bag and the beans move around like a box of cereal, move on to the next bag! If a bag has lost the seal, you don't know if it has been 'open' for a week or three months.
Second, the debate goes back and forth about freezing or not freezing. Do what fits your life style best.
Third, the more you can limit exposure to oxygen until you use the bean the better. Coffee beans are like a lot of other items, they can become stale over time if cared for properly.