New Fish but don't know what it is

Hey guys, A friend gave me a fish and told me it was a Black Molly, but I'm not sure if it is or not.

He/She is also swimming like sideways. Not sure why.

Any help would be appreciated!

Hey guys, A friend gave me a fish and told me it was a Black Molly, but I'm not sure if it is or not.

He/She is also swimming like sideways. Not sure why.

Any help would be appreciated!