Let's get an real erc20 contract on the mainnet and see how it goes.
Take a look at the contract on Etherscan. If the contract is verified, etherscan will show you the source code, abi and some other information. You can download the abi from .
Save and load it in the code.
We use weth address, abi and provider to create a contract instance.
Get the information of the contract is easy.
Oh, vitalik has 0.05 WETH.