I just wanted to ask why there isn't a seed given/created when you import a wallet using private keys?
I imported my wallet with them and I did set a password but can't seem to find anything about a seed. Is that normal?
First, you have to understand how seeds work.
A mnemonic seed is a 'big random number'. This number is then encoded into words (your 12/18/24 word mnemonic seed).
All private keys inside a wallet created with this seed are derived from this 'big random number'.
You only have imported a private key. There is no way to find out if there is a seed which would reproduce this address.
So.. yes. It is normal.
If yes,is there a way to get a seed so that I have another way of backup of my funds?
The only way to 'get a mnemonic seed' is to create a new (HD) wallet. Most wallets nowadays are BIP39-compatible HD wallets.
So, to backup your coins with a mnemonic seed, choose a wallet software, create a new wallet, backup your seed and send your funds over to that wallet.