Infura provides access to the C-Chain only.
The C-Chain supports the Ethereum Virtual Machine (EVM), allowing Ethereum developers to deploy Solidity smart contract dapps onto the C-Chain. Dapps can run on both Avalanche and Ethereum. Avalanche Platform's C-Chain is EVM-compatible, but it is not identical. There are some differences you need to be aware of, otherwise, you may create subtle bugs or inconsistencies in how your dapps behave.
The following instructions assume that you already created an Infura account and Web3 project.