Leninists are the most common form of Marxist.

No, they're not. There are plenty of Marxists that doesn't even self-describe as Marxists - in the same way that physicists who study and use Einstein's theories don't self-describe as "Einsteinists." It would be silly. Even anarchists accept Marx's critique of capitalism - does that make them "Marxists?" Generally, Marxist-Leninists use Marx's image in the same way the Catholic Church uses images of Christ - ie, they care more about "owning" Marx for political capital than anything Marx actually wrote or meant.

Also weren’t you saying that liberals are all about capitalism earlier?

Capitalism is a feature of liberalism.

How can you be a liberal and not support capitalism?

Lots of liberals purport to criticize capitalism - you simply have to look at politicians like Bernie Sanders to see that. However, their criticism is purely constructive - their purpose is to protect the liberal status quo by reigning in the most overt excesses of capitalism. Their purpose is most definitely not to dismantle it. Dismantling capitalism (whether through peaceful means or otherwise) is where the left starts - it doesn't matter what CNN or France24 decides to call "leftist."