A step through bike is going to weigh more than a standard bike so be sure that is what you need. More than 95% of the bikes sold are not the step through type in the USA. People have been using regular caliper brakes for one hundred years and the disc brakes are needed for heavy mountain bikes and tandem bikes but are more of a marketing gimmick for road bikes. Far more brake failures and crashes with people riding bikes with hydraulic brakes where a failure can take out both the front and the rear brakes which cannot happen with cable type brakes.

Most important with hills is to have a granny low gear that is low enough that you can go up anything. A bike takes 20% of the effort of walking as your weight is supported by the bike. Unless you are in too high a gear. People do need to learn to use their gears, not much different than when driving a car in the mountains with a manual transmission where the driver needs to sense that the engine is struggling and shift into a lower gear. If a bike does not have a low enough gear it is a $50 cost to have larger rear cog installed by a bike shop so you do have this "granny" gear.

You save 50% to 80% with a used bike bought from its owner on Craigslist. If it turns out you do not like it you will still be able to get all your money back when you sell it yourself.