FCT is a blockchain platform that allows the storage and validation of documents. It records entries in a unique list that distributes a copy of the documents to everyone involved in the transaction. However, these entries can not be tampered with or altered after they are added to the list.
This type of setup is meant to be used as an audit trail for businesses that need to maintain integrity in their chain. Your Factom investment is a decentralized, distributed protocol that is run on top of bitcoin. FCT is a platform for global data integrity.
You can buy Factom on several top exchanges. The most abundant trading pair for this coin is for Bitcoin, but it also has Ethereum pairs on a few exchanges should you wish to exchange these tokens instead. The volume, however, is heavily slanted toward the Bitcoin pairing though so it most likely will offer the best deal for your purchase.
The only options at present for storing your coins is either through the official wallet for the project or through a paper wallet. A paper wallet is the most secure option as your coins cannot be stolen. However, the official software wallet will give more convenient access to your assets.