Also note the difference(s) between Organizations (which you mention in the thread subject) and Companies (which your question was about).
Orgs can own companies but they're not the same thing... They are sort of like proxy citizens, but Orgs don't work, produce goods etc. Each Org does give you an additional 20 inventory spaces, which can be very helpful and a big money saver through buying food/weaps in bulk when the price is right. Orgs let you gift yourself without having to ask a friend to do it. You can also vote up articles with any Orgs you own. I think they're good to have once you can afford it, but not before buying say a house for example.
Companies OTOH require raw materials (which you must buy) and employees (which you must pay and monitor). Licenses can add to your costs. It's possible to make money but it may well cost you money. I would say hold off and read up on it first. If and when you do choose to own a company, buying an existing company may be a better idea than creating a new one.