So bitcoin's API, commands, daemon feature is same at all other alt-coins?
Generally, no.
Some forked coins may have the same API, but doesn't have to.
Just google "your_coins_name developer api" to find the correct API for your coin.
And eth ERC20 token does not have any source github, API, commands, daemon, right?
ERC20 tokens are just coded contracts. You may found them on github. This depends on the developer.
Regarding commands and deamon, look
here.
You don't need to run a daemon for an ERC20 token. They run ontop of the ethereum network.
You might run an ethereum daemon if necessary.
ERC20 is a protocol running on top of Ethereum network..
ERC20 describes rather a
standard for tokens, than a protocol.