When I first started brewing coffee at home, I had a fear that if coffee was not as fresh as possible, I would be missing out on its full potential. I stored my coffee bags, when opened, in a plastic tub, and would often think about whether my storage setup was adequate. Indeed, freshness and proper storage are essential components of making the most out of your coffee, but I always found storing coffee at home confusing. Do I need a vacuum sealed container? Will my coffee be okay in a cupboard? Should I only open bags of coffee when I have finished one that is already open?
At home, I store coffee in the cupboard in a container. The container is from Steampunk Coffee and fits one bag of their coffee in it, which is ideal. If I don't have a coffee that would easily fit into the container, I'll usually keep the coffee in the bag that it was in. That bag goes on the top shelf in a kitchen cupboard. That's how I store my coffee. I do not have any more fancy equipment for storage. I rely on the coffee bags and my Steampunk Coffee container.
The main rules you need to remember are:
Don't store your coffee in the fridge.
Keep your coffee in a cool and dry place, away from moisture. A kitchen cupboard is fine so long as you do not expect the cupboard to get really warm.
Storing coffee in the bag it came in is usually fine. If you are worried about freshness, use one of the plastic bag clips that let you seal bags.
If you have one, you can move your coffee into a storage tin (ideally one that light cannot get into and that will keep your coffee cool). This is optional.
Coffee will not stale immediately after opening a bag. You'll still have weeks to enjoy the coffee before you will notice a decline in quality.
Storing coffee in the freezer is fine. Use this if you are going to go at least a month without touching the coffee. Store a completely sealed bag of coffee in the freezer with little to no air inside. Valves should be covered. Notably, consult someone more experienced than I on the freezing of coffee. The Manchester Coffee Archive has a very detailed account on what we know right now about freezing coffee beans.
What about freshness? Good question. I used to think about how coffee would depreciate in quality after opening the bag. While this is true, in most circumstances your coffee will be just fine and, at least in my experience, you will not notice any significant difference in taste for at least a few weeks (although if you have a more trained palate than I then you may disagree). And in terms of drinking coffee after the roast date, I have found coffee a month or even longer after roast (as long as the bag was not opened before then) can still taste amazing. After a few months I'd probably think about getting another bag of coffee.
I hope these rules convey my point that you don't need to overthink storage or freshness. Keep your coffee cool. Store it in the bag it came in or in a storage container. There is plenty of advice out there on how to store coffee. That advice might be good for some people. But if you are a beginner, what I have said above should be enough to help you preserve your coffee (although if you want to freeze coffee, you'll need to do a wee bit more research!).