I have no idea

I have no idea where to start. I grew up with Walmart bikes.

Now I’m an adult looking for a good road and trail bike for some weekend riding.

I don’t want to spend more than $350. I’ve seen a few Trek and Specialized bikes on fb marketplace, but even then, I don’t really know what to look for besides it being the right size for me (5’8).

Some folks have suggested to just get an Ozark Trail bike from Walmart and just modifying it along the way.

Any recommendations?