If you're thinking about starting a business, you likely already have an idea of what you want to sell, or at least the market you want to enter. Do a quick search for existing companies in your chosen industry. Learn what current brand leaders are doing and figure out how you can do it better. If you think your business can deliver something other companies don't (or deliver the same thing, but faster and cheaper), you've got a solid idea and are ready to create a business plan.
obrt: ≈ sole proprietorship; several types: slobodni, vezani, and povlašteni obrt (free, tied, and privileged proprietorship registered according to profession; tied and privileged proprietorships are those only master craftsmen can register,) paušalni obrt, obrt-dohodaš, obrt-dobitaš (flat-rate proprietorship, income tax p., profits tax p.; these are registered according to the type of taxation; first two are obligated to pay income tax and the last one is obligated to pay profits tax), sezonski obrt (seasonal proprietorship, that runs for a limited number of months during a year)