The legal requirements to sell soaps/cosmetics etc. will vary from state to state. Here in Illinois, you do not need any special licensees for selling bath and body products, just have to follow the normal procedures/regulations for starting and running a small business (again, this will also depend on the type of business structure you go with, sole proprietor, LLC, etc.). Now in Florida - you can only sell soap as in true soap, nothing more.
In addition to the legal regulations regarding a business set-up, retail sales tax, filing income taxes, etc. you should familiarize yourself with the FDA labeling laws as they apply to soap, cosmetics and drugs.
Liability insurance can be sometimes purchased through who you may have other homeowners insurance through, RLI (there are sales limits with this one) or the Handcrafted Soapmakers Guild or Indie Beauty Network that offers an insurance option with your membership in the groups.