Certified GKH Gardening Expert
It depends on your cultivar. Many varieties don't need a second plant for pollination but you will have more fruit if you do have more than one blueberry bush.
Their coming back depends on the hardiness zone you live in and what the hardiness zone is for your cultivar. For example, if you live in hardiness zone 8 (you do) and buy a blueberry bush rated for zones 4-7, it may not come back. The USDA hardiness zones help determine what temperature a plant will thrive on based on average annual minimum winter temperature.
Zone 8 is tricky for blueberries because they need a certain number of chill hours during winter to produce fruit the next summer. Be sure the blueberry bushes you buy are rated for zone 8. They also need very acidic soil.
Here are some articles that should help: