Conversation so far:
how do you know what side of the street to park on
Parking on the left, or facing traffic is illegal.
why is parking on the left side of the street illegal
By parking on the left, it would require you to drive on the left side of the roadway, violating this law.
is parking too close to another car illegal
It's not illegal, but is a little discourteous to park so close to another vehicle.

Question: why not
Self-contained rewrite: why is it not illegal to park close to another car