Where you are going to this conference is a bit north of San Diego.
There is always,
Campland on the bay.
If you want something inland there is
Santee Lakes a really nice place
The
KOA that was mentioned is south of San Diego in Chula Vista, I enjoyed my stays there.
If you want a really nice place there is there is
Chula Vista Resort nice views a restaurant in the marina a very nice place.
All of these are a bit of a drive to where you are going to to the conference.
They all have maps and a clickey for directions so you can see how far you are from where you want to be. These will give you a start on the planning I hope, good luck.