> To take control and take advantage of your yet -unknown/hidden abilities , all you need is to find the way (key) to set free/to bring out the greatness of these qualities Grab hold of > to have influence /control over ( another meaning) .Drugs have grab hold of him/ let's grab hold of someone who can help us Secret('s ) wonders > Qualities you do not know you have , but they will amazed you when you find out)

Hi Alex, This sentence is obviously from a passage of advanced English. It is a deep and abstract comment which would need quite a lot of concentration for a native speaker to understand well in the context. It would be important to understand the entire context in order to help you fully. "grab hold of" = "take firmly" "take advantage of" = "use" The other words have their ordinary meanings.

Ok. She should have identified previously her "secret" and the "wonders" of that "secret". But she cannot make good use of these "wonders" at the moment. In order to make good use of these "wonders", she believes that the only thing she needs is "the key to unlock its [the secret's] splendor". Hopefully, she will define this "key" and also why the secret has a "splendor", which is currently hidden. If she doesn't explain her terms in her statement, then she is using abstract and figurative language just to impress, and not to say anything really meaningful. This is quite possible!