Download & Install MetaMask.
Click here to add the Rinkeby, Mumbai, & Fuji networks to your wallet.
Load your wallet with testnet gas.
Minting & beaming collections & NFTs costs gas.
Every chain has a different gas token (e.g., Ethereum uses ETH, Polygon uses MATIC). You will need gas to mint & beam collections & NFTs.
Here's a list of testnet token faucets (these tokens are free!):
Prepare a digital asset.
Have a file ready to upload as your NFT.