How much room do you have on the sides? Can you locate the garage in front of the old garage with a side entrance? Can you locate the garage in the backyard toward the side property line?

Here’s a better pic of the side of the house and driveway. We can park 2 cars on the driveway side by side and one on the gravel near the wall

Forgot pic

Start by finding out from the city what distance all building parts must be setback from the property line. Also, find out how far the face of your house is actually set back from the property line. The difference between these two is how much space you have remaining at the front of your house for constructing more house/garage.