You are likely confused as to what to look for.

You want a round not oblong or ovular melon. The tap root should be raised and dry. If it is indented the fruit was harvested too early.

The field spot, where it rests on the ground, should be yellow to orange. If it is white it is unripe. The stripes should be distinct and solid. If it has crusty dirt like stuff that doesn’t brush off easily that’s a good sign as that is scar tissue from where it leaked sugar.

Finally it should sound hollow when tapped not dull.