While the home lawn may suffer from occasional disease attacks, they are generally not that frequent or severe.
The weeds that you will generally find present in your lawn will be other grasses, sedges or broad-leaved species.
A range of pests will attack the turf in a home lawn. How severe the attack on your lawn is is highly dependent on the specific pest involved, how healthy or stressed your lawn was before the insect attack, and on the variety of grass you are growing (how good your grass tastes to the pest!).