I agree with Michael.
Using slang is like wearing a badge to say that you belong to a particular group. Within the English-speaking world, different communities have their own own slang. These might be regional, generational, ethnic or cultural. People don't tend to use slang when they are talking to people outside their own groups. It would also sound very silly if an British schoolteacher tried to use the slang of a New York teenager, even though they are both English speakers.
While it might be useful for you to understand common expressions, such as dough, that you might come across in the media, I would advise you not to use them until your English is much better. Please don't think that you can improve your English by using slang. A foreign learner needs to have near-perfect English before they can use slang without sounding strange.