Who gives the block to the miner Im still making my way into the block-chain world. I have been reading a lot. 

I want to know who gives a block to the miners?, then they compete to get the challenge right, whoever gets the challenge right has the privilege to add the block. My confusion is how is a block created in the first place? where does the transaction come to the pool of miners?
Nobody gives the block, the miner comes up with it. Think of it as designing a mansion. The possibilities are endless: it can even be an empty block without transactions (there is no mansion, just a garden shed). It only needs to be valid in two ways: no conflicting transactions (the design is physically possible to build) and it has to be cryptographically secured (you have to go through the legal bureaucracy before the construction may begin). In bitcoin world, only the last part takes any significant time, and it doesn't depend on your design at all, it's pure luck.

Only certain blocks are valid, so miners have to spend time manipulating the contents of the block until it satisfies the target hash. The transactions however are merely suggestions, the miner has the complete authority and can "build" whatever they want. When they work on the block to make it meet the difficulty standard, they only "manipulate" the parts that don't matter.