@Benson Gee Don't worry about it, the more questions you ask, the better are your chances of making your first deal successful!
I believe Zillow lists both MLS and FSBO properties and as mentioned above, may not pull everything listed on MLS. I probably should have phrased my statement a little differently.
When you put a property under contract, there are terms that need to be agreed upon like price, closing dates, inspections, etc. Depending on the market and deal, you terms may or may not include an inspection period. As an example (but not a proposal..) If you have a property you know is an absolute bargain and you know will require a lot or very little rehab, you could offer an all cash deal with short or no inspection period in your offer. This could make it easier for the seller to accept other terms in your offer such as a relatively lower offer price.
The easiest way to understand the buying process where you are buying is to speak with your agent. In AZ where I am currently putting in offers, my agent's standard contract has a 10 day inspection period in which I can get an inspector and contractor in the property and make sure it meets my expectations before closing.