Interacting with Purebet is purely on-chain. This means there is no need to use a username, email, password, passport, selfie with your passport in your left hand and your dog in your right arm outside your house while squatting. All you need is a Solana blockchain wallet and some funds in it. There are a number of Solana wallets, the most popular of which is Phantom wallet (https://phantom.app/). In order to bet at Purebet, you will need USDC in your wallet. In order to pay blockchain fees, you will need some SOL, the native token of the Solana blockchain. $1 worth of SOL will pay for months worth of bets, but getting $5 worth will help cover rent exemption if you have many pending maker orders. Both USDC and SOL can be obtained from a cryptocurrency exchange like Binance or Coinbase (just ensure you are withdrawing the USDC to the Solana blockchain), or it can be obtained within the Phantom wallet itself, using your card or Apple Pay (future integrations by the Phantom team will expand this).
Go to https://purebet.io and click Go to Exchange. Then connect your wallet on the top right and you are ready to go. When you place a bet, your wallet will pop up asking you to complete the transaction.