Describe one situation where you would consider thermal energy as useful energy and one as wasted energy

Please help me.

Heating your house in winter is - for most of us - useful.

The heat produced by your car in summer is wasted.

I will give you two examples that involve the same energy source so you can make
a direct comparison:

(1) The purpose of an electric drill is to convert electrical energy to rotational
mechanical energy. Unfortunately, the process has some losses due to the
imperfect efficiency of the motor. This lost energy takes the form of heat and
since it isn't used, it is wasted and only adds to the temperature of our world.

(2) An electrical toaster converts electrical energy to heat; and this process
when you want it, is virtually 100% efficient (examples of inefficiency are:
some heat escapes the toaster, the power cord gets warm, and so on ...).
So in this case the heat generated is useful.

In my house, the fire generates heat usefully. The light bulbs are intended to produce light. They also produce waste heat.

Energy is never wasted .It can be used to do work and at the same time heat the surroundings.