Sell primary residence to purchase multifamily

[Brandon Thomas]

I'm 30yrs old and have been an electrician for 13 yrs, I currently live a high liability no asset( except house) life style. The current housing market has allowed me to gain $120k equity and I would like to sell and buy a commercial multifamily unit.  I have waken up early, put my boots on and gone to work for too many years. I completly new to this arena and would sincerely appreciate any feed back.

1. Not sure what cap rate is good for a multifamily home in San Bernardino,Ca

2. Is it best to negotiate a price that reflects that desired rate?