NFT Marketplace is simply a platform that allows users to mint, share, and trade NFTs. It is entirely online and accessible to the general public. To get started, all you need is the necessary hardware and software.
Because NFT marketplaces are decentralized ecosystems, look for a blockchain that hosts more DeFi projects than the others. For example, Solana is a blockchain that facilitates DeFi more than the others. Get a clone script, host it online on a domain, and follow the steps to integrate it with the blockchain.
The NFT marketplace can be developed gradually with each scheduled update, which optimizes the experience by studying user data and analytics. Find professional programmers and software engineers to modify the clone script's source code.
This will all take time. It is a gradual process that will not be completed overnight. Take it one step at a time. If necessary, hire a professional firm that specializes in NFT marketplace development.

I hope this was helpful.