>>2005753department store crap are called Bicycle Shaped Objects. BSO brands are huffy, murray, magna, ... I'm drawing a blank but there's a lot more, and outside the US each country has their own. mongoose started with high-end bmx, then they also made good MTBs for a few years in the early 90s but then they got bought and everything since is bsos. if it says mongoose, don't buy until you know how to spot that good era with nice components.
the bike shop brands are what you want. they may be low end but acceptable on up to high end.
there's a million of them, and good stuff from smaller boutique brands may not be made anymore but are on the used market.
look around your local Walmart equivalent and avoid those names. look irl or online at bike shops and go for those names.
one reliable identifier for decent steel bikes was they were made of decent chrome molybdenum "cro-moly" or "cro-mo" steel alloy which is advertised with a decal usually under the top tube on the seat tube or sometimes on the down tube near the head tube. if it says double or triple butted, even better. department store bikes never had this (although a few tried to make fake-out decals for a while, look them up on your phone if it looks weird)
there may be decals for aluminum but it's not as codified but you can always look it up. carbon is carbon, you just have to trust the mfr.
I would suggest using the bike buy general for good advice
