Where can I buy new Cryptos?

As a crypto enthusiast, I'm constantly on the lookout for new and exciting cryptocurrencies to add to my portfolio. Could you please guide me in determining the most reliable platforms or exchanges where I can purchase these emerging cryptos? Are there any specific criteria I should consider before making a purchase, such as the reputation of the exchange, the liquidity of the asset, or the project's roadmap and team behind it? Your insight into this ever-evolving market would be greatly appreciated.