A couple of years ago I purchase a little Bitcoin. I don't know where I purchased it through, but I do have the Wallet Name, Wallet Address, and Wallet Key. How do I retrieve it? Can I access it through any exchange? I'm confused here a little.
Not sure what you mean with Wallet Key but if you mean the password for access to your wallet in the exchange then this will only work in that exchange.
Please search for your address here to verify that your coins haven't been transfered somewhere else.
If you don't have the seed then you better remember where you purchased your bitcoins! :/ Maybe checking your search history or your inbox?
I'm a little bit confused by what your statements, an exchange shouldn't give you any wallet name, or key. You usually only have the address that you deposit to or take funds from.
If you have the private keys, you could easily get your funds by importing them to a real wallet (Electrum, Bitcoin-qt etc.)
Note that a lot of exchanges got hacked or closed in the last couple of years, use the wallet address you have in blockchain.info and see If it actually contain the funds at least.