You can't browse the market from the web. It is in-game only access.
Account unlocks affect your entire account. Character unlocks just affect the character you use them on.
Note that any real money you spend on the game for anything will make you Premium and put you under the Premium limitations.
Also you might look at the Premium Pack or whatever it's called exactly. It is a package of unlocks IIRC and is I assume a better deal than buying them individually. There's also a Newcomer Pack, or something like that, that has some other stuff in it you might check out too.
Yes, I knew all of that info already. However, anything that you mentioned above doesn't answer my question of "how to buy account unlocks."
Those items I mentioned above have both symbols of character and account unlock. However, when I click on the description and hover over the item, it only gives the option of character unlock. So "How do you buy an account unlock?" Not trying to be rude, but all that other stuff I already know. I know that an account unlock unlocks that specific item for all my toons on one account. I don't need that bit of info. I just need to know where/how I can get the account unlocks.....