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.
why is it not illegal to park close to another car
If the road is a public road with no road markings, lines or signage to signify that you are not allowed to park there, then it would seem that you are perfectly within your rights to do so.

Question: what makes a vehicle legal
Self-contained rewrite: what makes a car street legal