Q&A: Businesses & Hobbies

I saw in lilsimsie's review that there are a few businesses already set up in the new world which we can visit ourselves without owning them, to learn skills and attend classes etc. Do you know how easy it is to set this up? ie. if we want to set up an 'unowned' business, such as a cinema, for our own sims to visit, do we have to set it up by using another sim to buy it? Or is it something we can do in build mode by just placing certain items? 

For businesses owned by other sims, if we visit there will we see those other sims running the lot or does the game generate a random sim to work there like it does with the current retail system?