need more memory on my phone I have the iphone 5 ios 6 and I have two backups on there and it tells me 
I need to delete one of my backups. Would this delete my stuff already on my device even if it says that it will delete  all backup data from icloud?
No it will not delete the data from your phone. A backup is stored on your PC/Mac or on iCloud but the backup is just a reference copy of what is already on your phone. Deleting a backup will not delete the current data on your phone.