At first, you need to create a crypto wallet(What is a crypto wallet) like Metamask, which is used for storing your ETH and transacting on the blockchain. You will complete the transaction with a unique address that is generated by the crypto wallet. All the transactions related to your wallet address will be displayed on etherscan.io, you’d better check the transaction on the website after you have completed the transaction.
You can trust that your wallet is secure. It was never operated without your permission. You must manually approve or reject each action to ensure that it is based on your consent. But don't worry, it's easy.
Secondly, you can obtain Ether (ETH) through a cryptocurrency trading platform similar to Coinbase. ETH is the fuel for transactions on the Ethereum chain. You need to use ETH to casting or buy NFT, and to pay a Gas fee to complete the transaction (what is a Gas fee).
Finally, move to 「Create NFT」 at the upper right corner of the homepage, and choose your wallet type to connect your wallet.
Finally, move the mouse to the profile picture in the personal center at the upper right corner of the homepage, and click 「Log Out」 in the drop-down menu