Good question. I would say, you would have to agree witht he prime concepts of Classical Marxism. You know, Critique of Capitalism, desire to obtain classlessnesss and a lack fo state through means of socialism, revolution tasked with creating Socialism, etc. Leninism is not considered Marxism because it contains two distinctive properties not found in original Marxist thought; those being Vanguardism and Democratic Centralism. Vanguardism is, in short, the idea that since reality conflicts with the idea of the proletarian gaining a common revolutionary consensus, a small group of elite revolutionaries must take charge in leading a revolution and safely paving the way to Socialism by all means. It goes much deeper, but you know, a quick run down
. Also, Democratic Centralism, the idea that the Party should have complete democracy in debating, and they must act unified once having come to a decision based upon "majority rule". An extremely brief run-down, but if you like this along with Marx's original ideas, I would qualify you as a Leninist.