You can start with the pseudo-decentralized exchanges, they usually charge little to no fee, check this list:
https://www.coingecko.com/en/dexAlso check this slightly outdated thread which list exchanges and its listing fee:
Crypto exchanges comparison [trade fee + listing fee + age + mobile app + more!] just note that the 'free' in big exchanges would for sure require you to have a solid community so if you're just starting and looking to list in centralized exchanges, target the small markets first and gradually climb up.