What exactly is the spot market?

The spot market is the market where you can buy goods for immediate or near-immediate delivery. For example, my last apartment was heated with heating oil, which we needed to purchase directly from the supplier. Looking at their website, if I wanted to purchase heating oil right now it would be 0.7299CAD/litre and it would be delivered early next week. This is the spot market. Bilateral transactions mostly between buyers and sellers but also sometimes through intermediaries.

Where do you find the spot market ? You need to find either sellers from whom to purchase the goods or buyers for your goods. Depending on the goods, it might be as simple as going to a farm and talking to the owner and much more difficult if you want to buy a single barrel of petrol.

Where is the price quoted ? You would obtain a quote either directly from the seller or from an intermediary (e.g. marketplace, trade association, etc).

Is it physically settled at some future date ? Depending on the nature of the goods, the size of the trade, etc the delay for the delivery of the goods may not be immediate but generally it wouldn't be, say, multiple months or years ahead of time.