My husband and I are flying into and out of San Diego in mid-April. We have ten days to explore (it is our first time in Southern California). We would like to travel out to Joshua Tree National Park and would like a recommendation on how many days to stay in the park. In addition, we are planning on spending a few days in San Diego. However, we need some suggestions on where else to stay. We would like to enjoy the natural beauty of the area but would also like to have access to restaurants. We will have a car. Any suggestions?