A NFT is a Non-Fungible Token. Non-Fungible implies uniqueness or irreplaceability. A non-fungible token represents proof of ownership. More info can be found here: https://ethereum.org/en/nft/
Think of a blockchain as a ledger or receipt that holds transactional information that is irreversible and decentralized. Decentralization creates a system that has no single point of failure that can provide transparaceny into the transactions on the blockchain. Anyone and everyone can look at this information to verify themselves.
Your Seed Phrase (Secret Recovery Phrase) is generated during wallet creation. This is by all accounts and purposes, your wallet’s master password. It is of extreme importance that you write this down offline and keep it securely.
If you lose your seedphrase, it is recommended to move your wallet contents to a new wallet with a new seed phrase. This is so you never are locked out of your wallet and contents.
A wallet is your ID on a specific blockchain. Wallets can be thought of as a place where your coins, tokens and NFTs are stored. For Ethereum you may have one address/wallet and for another network it may be different.
A hot wallet is one that is connected to the internet/applications and could be vulnerable to stolen funds or online attacks. A cold wallet is one that is not connected to the internet. This is more secure but less convenient.
Most simply put this is a network fee. The fee paid is used to attempt a successful transaction, including minting or trading NFTs. Gas fees are dependent on the usage of the network.