This link nicely explains the difference between lower order and higher order properties
First-order properties and relations are those that can only be instantiated by individuals. For example, redness can be instantiated by apples and cherries and being married to can be jointly instantiated by Bill and Hillary, but no properties can be red or married. It is natural to suppose, however, that at least many first-order properties and relations can themselves have properties and relations. For example, redness might be thought to exemplify the property of being a color and being married to might be thought to exemplify the property of being a symmetrical relation. Once we think of second-order properties, it is natural to wonder whether there are third-order properties (properties of second- or, perhaps in cumulative fashion, of second- and first-order properties), and so on up through ever-higher orders.
What if it could be shown that only 1st order properties could be seen without the seer taking up a further propositional attitude toward them.
Would that mean that the Tractatus can only rule out the metaphysics of 1st order properties?
My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless, when he has climbed out through them, on them, over them. (He must so to speak throw away the ladder, after he has climbed up on it.)
He must surmount these propositions; then he sees the world rightly.