It IS the roast that is the difference. The only real difference in the beans is that some beans taste better at a higher roast than others, so they are more appropriate for espresso. Your Italian grocery coffee company may be using the espresso label for marketing purposes, but in general, espresso coffee beans can be the same beans that are used for "regular" coffee, but roasted to a French or Italian roast level, which is darker than City or Full City.
Since the advent of Starbucks, many roasts are much darker than they used to be. Dunkin' Donuts coffee, which is a Full City roast, used to be the norm, but now a French seems to be what you can buy.
I roast my own coffee and take it to just into the second crack which is, generally, a Full City roast...a point where the character of the coffee predominates rather than the flavor of the roast. There is more information about roasts at Sweet Marias where I buy my green beans, and reading through the site will give you way more of a coffee education than you probably ever wanted.
So, yes, you can use the coffee you have to make brewed coffee. It will probably be roastier than you would normally have, unless it is just a marketing ploy, in which case it will taste normal. Consider how long you have had this coffee; if it has been shelved for a while "normal" probably won't be all that great, since freshly roasted coffee is, generally, way better than old coffee. But as long as the oils aren't rancid, it is more likely just going to be bland.
I found a quote from this article
One thing you may not want to do with a press pot, especially a larger model, is use beans roasted less than 2 or 3 days before. What, am I crazy? Nope. There's a problem with ultra fresh beans and it is called "bloom". When beans are only a day or two off the roast, they contain heaps of Co2. Heaps of it, I tell you. That Co2 will translate into a massive bloom of brown suds on top of your press pot, possibly overflowing, but also making it easier for big particulate matter (your ground coffee) to hop and skip over the top of the filter portion when you first apply it. Bloom looks cool, but can make using a press pot more difficult.
The poor filtering part sounds questionable to me, so I googled it and found a few bloom-related comments on this blog post. It seems like some people start timing their soak time only after they see bloom.
This seems like the real reason to me. I know for sure that the air content in ground substances can vary significantly: one cup of flour can contain double the volume of another if one is loosely sifted and the other is compacted. The above quote is accurate about that in my opinion.
Apply this logic to coffee and in order to produce an accurate, general recipe for how long some compounds take to come out of coffee grounds, you need to factor out a variable between coffee grounds: how much air is in the grindings. Maybe the first small pour will saturate with coffee compounds, or drop in temperature quickly, reducing how much it can extract from the grounds. Once it squeezes out all the air, the rest of the water is poured in to do the real extraction work.
Best Answer
You need to know what coffee you want to drink. Your question is like asking "What do need to know before buying meat cooking tools". If you want to eat your meat as BBQ, you need a grill and tongs. If you want to eat it as meatloaf, you need a meat grinder and an oven. Similarly, with coffee, you need to know what coffee you want to drink. Different types of coffee are made with different processes, and each process needs different tools. You need a dripper and filters for drip coffee, an espresso machine for espresso, and so on.
Your decision will be probably based on
If you are confused by the wide range of coffee methods and think "I don't know how each of these coffee types tastes like, how do I know which one to choose?" I would recommend to start by the second criterion (money) or third criterion (effort), depending on which one you are more pressed for. As an example, if you are a middle class person to whom it doesn't matter if they will spend 100 or 200 Euros on a tool which will be used as a part of their daily routine, go by effort. Look up what it takes to make coffee with the different methods, and think which you can imagine yourself doing. Then try coffee made with this method (if you need special tools for it, maybe you have a friend who has the tools?). If it is good enough for you, get the tools and start brewing. If not, move on to the next method on the list. Money-first would work similarly, but you rank the tools by price rather than effort per cup.
The first criterion - taste - is probably the one which is most likely to result in personal satisfaction, but you would have to know what you want before settling on a method, and it would be very difficult to find a way to taste all the different types of coffee and to develop a taste for each. Note that, if you are just starting out with coffee, your taste is also likely to develop and shift over time. So, I wouldn't recommend taste-first for people going for their first set of tools.