Battery and Assault

The shove is a battery - you can file a police report if you are the victim.

In California, for assault to be actionable, you need to have reasonable fear of bodily injury. as has been pointed out, a shove is battery, but this does not sound like the kind of dispute thats should rise to a civil lawsuit. If this is a longstanding feud, maybe you are best off getting some type of mediation to work it out, or at least establish a peaceful co-existence truce.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.