Shelf help/guidance

Just put your shelves up high enough you don't dent your melon on the way past.

Very possible that wall doesn't have studs.

I put a shelf up in bathroom , i just use mollies , my walls are foam.

Mollies work fine !

You might consider going right through the wall and adding a narrow shelf at the same height in the bedroom too. Then you could bolt right through the wall and support both sides firmly.

Barring that, I would find the studs with a stud finder and put a piece of plywood across the wall. The plywood can have screws coming from behind it that would support the shelf unit, and then use more screws from the outside into the studs in the wall.