Benefits of Web 3.0 is you can program money. There can be nice economies that have their own ecosystems and incentives to use the network. This increases competition for internet monopolies like facebook. It also takes the middle man out of many interactions because the users can trust the protocols rather than people.
A token is fungible or non fungible asset created on blockchain networks such as ethereum & written in smart contracts. It is basically a programmed currency often with a fixed supply.
You can create a token on Ethereum by coding it in smart contracts. The standard for tokens is ERC 20 if they are fungible tokens, or ERC 721/ERC1155 for nonfungible tokens.