Any known tool or website can translate the given online contract into ligo? For example, KT18fp5rcTW7mbWDmzFwjLDUhs5MeJmagDSZ, can I review the logic of this contract in ligo somewhere, however michelson would be too difficult for me to grasp it.
The compilation goes in the other direction: from Ligo (or another high-level language) to Michelson. Michelson is designed to be easier to read than other VM bytecodes but reading the source code is usually much easier.
In the case of the contract you mention (the FA2 from the Wrap protocol), a quick search pointed me to the following repo: https://github.com/bender-labs/wrap-tz-contracts/tree/master/ligo/fa2.
FYI, I'm writing an experimental translator from Michelson to OCaml (not ligo).
The main caveat is that the generated OCaml code doesn't run -- It's just help human beings understand. :-)