Are you planing on mining litecoin with a antminer u2? 
lol yah but why??
EDIT: and i wanted to know about your trick!!
Oh you are serious ...
The antminer U2 can be used to mine SHA-256 based coins.
Litecoin is a scrypt based algorithm, so you cannot mine litecoin with antminer U2.
Here is a good place to start:
http://www.coinwarz.com/cryptocurrency
However the calculations does not take difficulty into consideration...
I can see that you knowledge-wise are almost starting from scratch, you could consider getting a used graphic card, I have seen a R9 280X sold for less than $100. And then mine a bit and get some experience. You will not make a profit, but you can make some experience, and after you will still have a ok graphic card to play games with.
Alternative strategy would be to invest in a PoS coin, like MINT or BC. Then use your normal PC to stake coins. But getting into altcoin is also a risky business.
But really, you should HOLD ON TO THOSE BITCOINS and not spend them.
sorry i forget about it
and i am planing to buy more btc can u help me??
EDIT:and bro i was thinking that to invest in new coins like in the algo of x11 and x13 i dont know much about them and how to mine them .
consider being hosted . read my hosting info thread
https://bitcointalk.org/index.php?topic=698679.msg7894701#msg7894701
keep your coins. and buy a lower cost hosted miner. they have some for btc and some for scrypt. you can use a cc to pay
feel free to ask advice as a newbie.
yah bro i am pming u about it