For this there is only one answer. The Toyota Corolla. It is the appliance of cars. It is very safe, it is very economical, it is one of the most reliable cars on the road in the USA, the AC is fine, and it is not that expensive. You can get a 2007 to 2010 with 70,000 to 100,000 miles on it in your price range in your area, and those cars can go over 200,000 on the original powertrain easily.
Don't expect a lot of power but enough to merge with fast moving traffic. Don't expect a lot of space but enough to be comfortable. Don't expect luxury as it is basic transportation. But as a first car it is hard to beat.
Back in the 1990s I owned one as my first car. The thing was indestructible and it fits exactly what you describe. Today they are just as reliable and durable.
There are other cars like the Mazda 3 and Mazda Civic as well if you prefer them which are nearly as reliable as well, I just think the Corolla is the best choice of the three.
Best of luck.