First Sync my iPad. Warn to have my iPad data deleted. Is it real? I want to sync the apps of my iPad on my iMac. iTunes warns me about the loss of the data stored on my iPad. Is this real? Can I make a backup of my iPad, Sync the Apps and then get my data back on my iPad?
Have you authorized your iMac with the iTunes account(s) that is linked to data on the iPad? If no, do it by going to Menubar > Store > Authorize This Computer. It should allow you to sync without the data loss warning.