My familiarity with Ventura, California, isn't exactly the sharpest. But, I have spent a little time in the vicinity (some friends have a beach house in Oxnard, California).

Ventura does a have "downtown", though it's more of a pedestrian area with several shops (don't think strip malls) along Main Street; it's worth spending an afternoon exploring, IMO. Will you have a car? Trips to Ojai, California, and Santa Barbara, California, would be worth it. If you're really feeling adventurous, you could even take a boat ride out to the Channel Islands. And, of course, there's always the beach.

As far as gay bars go, well ... I don't really have a clue there. The only bar in the area I've visited is on the beach in Oxnard; and, it's about as far from a gay bar as I can imagine!