Hello & welcome...
Getting a bike that fits you is more important than I can stress. If you're inexperienced with the properties of "bike fit," it's best to deal with your local bike shop (LBS). A well-stocked shop will have a variety of sizes for you to try and can order if not in stock. They also have the knowledge and the parts to get the bike dialed in for you. Plus, you get a warranty, and (typically) the purchase includes some follow up adjustments.
One thing I'll mention now before I forget: With the exception of some semi-recumbent or "foot-down" bikes, you shouldn't be able to put your foot down on the ground while seated in the bike saddle. Being able to do so suggests the bike is incorrectly sized for you and/or your saddle is too low. Dept store bikes don't offer the range of sizes; you typically choose based on wheel size.
A hybrid gets you plenty of bike without spending a fortune. Since you're riding smooth surfaces, avoid bikes with suspension; these add to weight, complexity and initial expense. A typical, entry-level hybrid in your size will be ~25 lbs, but even a top quality, $2k+ hybrid will still weigh a full 20 lbs. Don't worry about a few extra pounds; your bike should have a wide range of gears available to you. Less expensive bikes have heavier components, notably wheels and forks.
At your smaller stature, you'll be riding a small or x-small frame. Sometimes these have issues of "toe overlap" when the front wheel touches your shoe while pedaling during slow speed turns. There are ways to deal with this, but keep in mind that some bikes are designed to have minimal toe overlap issues for shorter riders.
Best thing to do is spend some time visiting the various shops in your locale. Check out the inventory and get a feel for the level of customer service. Take test rides and ask questions. It's very easy to buy the wrong bike, so don't rush the process. Don't get tempted by the first bikes you see. Always sleep on it. Don't waste your $ buy taking the wrong bike home.