1, ethereum official website: own Baidu.
2. Another very important Ethereum website: https://etherscan.io/
3. Check all the tokens on the Ethereum website: https://etherscan.io/tokens
For example, my tokens are wswhr, then you can query:
4, if you know the contract address of the token, you can directly through the URL to view: https://etherscan.io/token/plus tokens of the contract address.
Like my tokens: https://etherscan.io/token/0xa36336962bd92ad29aab202dcc208813acc5f19f.
In this link, you can see the number of tokens issued, the amount of holdings, and all the contract addresses that hold tokens.
5. To view address, you need to know the location of Ethereum: https://etherscan.io/address/Plus contract address
For example: https://etherscan.io/address/0xfa3cb69100615590a8474b3c9f5329eab73f891d
You can see all the actions about the current contract address. Whether the contract address, the wallet address, or the token address, can be viewed.