Choose the tokens you want to swap, click the connect wallet button to connect a web3 wallet like Metamask, input the amount you want to swap, and then hit swap.
The tokens will be swapped based on a liquidity matching algorithm native and unique to Uniswap, but the gist is it works like any other exchange.
With that covered, you can also use Uniswap to buy tokens that aren’t listed. You can input any token address, and if it has a liquidity pool, you can swap it.
This system has led to many new ico-ish coins coming out which are launching through Uniswap. These of course are incredibly risky, but this isn’t an article on risk management, this is an article on how to use Uniswap.
UniSwap Tutorial 2020: How to Use UniSwap Decentralised Exchange & Liquidity Pools.
"Uniswap" contains information about the following Cryptocurrencies: