>>1938246the biggest problem with the absolute cheapest bike is not the quality of the parts, but how poorly they are assembled, at the factory, and at the big box store.
Unless you are either very resourceful, diligent, and good at learning new things, and are going to apply that to immediately overhauling your new bike, or experienced, it will be awful.
The basic level of quality comes when you go past 7 speed and get an 8 or 9 speed bike. Not inherently, but as a signifier.
The other basic thing i suggest with cheap bikes, get one which is mechanically as basic as possible. If i had to buy a bike from wallmart, i'd buy a beach cruiser, with a rigid frame, rim brakes, and singlespeed. Absolutely not a full suspension 'mountain bike'.
As for what kind of bike is good for riding on trails, really, any. You can ride straight up road racing bikes on what most people consider to be 'trails'. That's a meaningless question.
In your budget I would suggest used. If you want recs from your local craigslist, post your height. If you want hot takes on new options you have, post em.