So bitcoin's API, commands, daemon feature is same at all other alt-coins?
And eth ERC20 token does not have any source github, API, commands, daemon, right?
No, each coins have their own features and APIs, you have to refer to that specific coin's documentation to find out.
ERC20 is a protocol running on top of Ethereum network, you can find links to github and docs here
https://ethereum.org/.