No different from learning a human language I think.
The first thing you're exposed to is its sounds and symbols.
They look & sound strange and your brain instinctively tries to make sense of them by comparing it to something you are already familiar with.
Then when you dig into it you begin learning vocabulary and grammar. You focus on that for a long time until the sounds sound less like gibberish and resemble something like what you've been practicing putting on paper.
Once you get comfortable with the constructs and stop focusing on them you can start conversing - putting more effort into what you're trying to say then how you would go about saying it.
After that then you can start picking up all the idioms, colloquialisms, cliches, double entendres, etc
The first thing you're exposed to is its sounds and symbols.
They look & sound strange and your brain instinctively tries to make sense of them by comparing it to something you are already familiar with.
Then when you dig into it you begin learning vocabulary and grammar. You focus on that for a long time until the sounds sound less like gibberish and resemble something like what you've been practicing putting on paper.
Once you get comfortable with the constructs and stop focusing on them you can start conversing - putting more effort into what you're trying to say then how you would go about saying it.
After that then you can start picking up all the idioms, colloquialisms, cliches, double entendres, etc
Finally you can start inventing your own.