Can I buy directly from Uniswap?

Excuse me, I'm a bit confused about the process of acquiring cryptocurrencies. I've heard a lot about Uniswap and its decentralized exchange platform. My question is, can I buy cryptocurrencies directly from Uniswap, or do I need to go through another process first? I'm particularly interested in understanding the steps involved in making a purchase on Uniswap, if it's indeed possible to do so directly. Thank you for your time and assistance.