Depends on your long term goals, but most people I know start with LLC especially when starting small from hobby to a profession. Most of the advantages of a corp. (S or C) are to do with how the company ownership can be structured, share allocation, going public, etc. Both LLC and corp allow for limited liability to the owner, which is important if things go wrong and/or your business is sued. (All of this is relative to US based companies - I have no idea about other countries).
This link offers an easy to understand set of differences:
https://www.myusacorporation.com/articl ... s-llc.html