Haven't been on Freedom, but have used the Concierge Lounge on other ships. I assume they all work the same way.
You ask about the Concierge Suite and the Diamond Lounge. I think you will find that there is one "club" - the Concierge Lounge. The lounge is open all day (and presumably all night). You can get coffee and pastries at breakfast hours. Cocktails and snacks are complimentary, but usually only from 5:00 to 8:00 P. M. You can go in, say, in mid-afternoon, and get some coffee, but not a drink. When you do get a cocktail, it will be served to you - it's not a "pour it yourself" situation.
Depending on how many Diamond and Diamond Plus members there are on board, they may have to open a second lounge during cocktail hour to accomodate the large crowds. On our last Jewel cruise, there were something like 140 Diamond and Diamond Plus folks on board - far too many to fit into the Concierge Lounge. Add all the folks in the suites, and you get the picture.