I would like to make a lab in the comfort of my home. Perhaps in the spare bedroom. My question is, how do I know what equipment I need? How do I actually conduct a scientific experiment? What does a normal biology lab consist of?

depends entirely on what sorts of experiments you want to do. Most biology labs costs at least 100,000 dollars to equip and many of the machines and experiments require by law permits relating to safety and hazardous materials.

It's also rather the wrong way of thinking about it.  Instead of 'what do I need for a lab', the question should be 'what do I need a lab for?'