To switch to RAID0 you would pretty much have to start from scratch and re-install everything. That means FIRST making a complete backup to some external media. Then after you have the new system running, you would copy back all the user-created files.
The basic problem is that there is no way to migrate your existing data to a RAID0 array. Even cloning won't quite do it, because your machine cannot boot from a RAID0 array unless it had a RAID driver installed as part of the original OS Install process, and I'm sure you did not do that.
What benefits? I don't use RAID0, but ask hard questions about this. It used to be that a RAID0 array was significantly faster that a single HDD - about a decade ago. Today the SATA 3.0 Gb/s new drives are so fast that RAID0 makes only a small improvement in speed. (Oh, and the SATA 6.0 Gb/s HDDs are NOT faster than those. Only the non-mechanical SSD units are faster than SATA 3.0 (aka SATA II)).
Understand that users of RAID0 really need to practise regular complete backups. A RAID0 array is twice as likely to fail as a single drive, and when it does everything in the array is lost. A reliable recent backup is the only way to recover.