I cant get software update

What software update are you talking about?

If you are talking about iOS 14, it hasn’t come out yet.

If you are talking about iOS 13, check your device is supported:

iOS 13 Compatible iPhones:

• iPhone 11
• iPhone 11 Pro
• iPhone 11 Pro Max
• iPhone Xs
• iPhone Xs Max
• iPhone XR
• iPhone X
• iPhone 8
• iPhone 8 Plus
• iPhone 7
• iPhone 7 Plus
• iPhone 6s
• iPhone 6s Plus
• iPhone SE

iOS 13 Compatible iPods

• iPod Touch 7th Generation

iPadOS 13 Compatible iPads

• 12.9-inch iPad Pro
• 11-inch iPad Pro
• 10.5-inch iPad Pro
• 9.7-inch iPad Pro
• iPad (6th generation)
• iPad (5th generation)
• iPad mini (5th generation)
• iPad mini 4
• iPad Air (3rd generation)
• iPad Air 2
• 10.2 iPad (7th generation)

There are no updates for an iPhone 6.