Best suggestion is head to a local bike shop and look at what they’ve got in your price range. As a beginner I suspect you want what is known as a hybrid, looks like a mountain bike, doesn’t have suspension (not needed on pavement or gravel bike paths), has the larger 700c wheels and somewhat wide tires. A Trek FX2 would be a typical type, has disc brakes, is a 9 spd, cassette with 2 gears on the crank, flat bar (not a drop bar like on road racing bikes), runs about $750 or so. Tons of options, just find one you feel comfortable on. Note that if the saddle doesn’t feel great, you can swap easily.