You need to understand that native speakers don't always use correct grammar. The second sentence contains what is called a 'double negative.' In theory, these should cancel each other out: "I ain't got no money" should mean "I do have SOME money." But that's not generally how it works. You can think of the two negatives as emphais. So, to understand "You can't take no chances," you might want to start by correcting the grammar: "You can't take ANY chances." Then the meaning becomes clearer. This is advising someone to be careful and not take chances.

Hi Viktoria! 1). Yes! Your understanding is correct here. The sentence sounds more like an imperative (instruction) you have given someone. "You don't take any risks!" 2). This sentence's context suggests a general reference to risk taking. It's a piece of advice you are giving someone. "You can't help but risk. ..." is a sentence used when we refer to someone habits or an addiction they have of some sort. E.g. in the situation of trying to be funny, you'd say "You can't help but risk making a fool of yourself, can you?"