They won't fit unless the hole & notch are the same as the one that came with the Walmart knife. Some brands don't even have a hole or notch and some have more than one of each.
My GE knife blades will not fit my American Angler or my Mr Twister, as their GE blades have two small holes and a stud on each blade (no notch). My AA and Mr Twister knife blades will fit in either one of those two knives, as will my Berkley Shark blade. All of those blades have a single hole and a square notch in the blade's butt end.
Looking at the ad for that Ozark Trail knife that you bought, I see the knife blades have only studs on each blade .... so I'd say you're going to have to find Ozark Trail blades to fit it.