Business vs. Company? Individual, Corporate vs. Firm?

I want to have a small building: the building will have 2 sister businesses. One will be a clinic type of operation serving outpatients. The clinic will sell health products too so both outpatients and customers. The other business will be like a medical center hosting inpatients. It will be a small business.

I want to register for a business this year mainly to secure the name. I cannot actually begin operations for a few more years. I need to fill in this form, and it is asking me if I want to register the business type as a business or a company, and if the business will be registered as individual, corporate or firm? All these terminologies can be quite confusing, perhaps someone could help me? With what I've explained above (the type of business I want to have), should I register as a business or a company?

I am going to be the owner, but I expect the investors will want a cut. I will also hire less that 50 staff.