I accidentally point File - CreateWallet in the wallet, and then all the data is gone, can I still get it?
Even if you didn't backup your wallet and while creating new wallet you did not overwrite default .wallet file that you can still get it. Just click open wallet and find default .wallet file in blockchain folder.
Path for UnA blockchain:
Windows: C:\Users\Username\AppData\Roaming\una
Mac OSX/Linux: ~/.una