At the moment I'm learning Solidity and using online remix to practice coding.
Question 1: As an exercise, can I construct a transaction and invoke my contract, for free (without inserting my contract to the block chain)?
Assume I have designed my contract and stored it in block chain.
Question 2: Do I need to design a web API to let people/users use the contract? or Etherum provide an API?
In general, I'd like to have a bigger picture in designing smart contract, and see how different components fit together.