Help with Polkadot Parity Wallet

I already asked this in the Polkadot sub but there's like 50 people online at one time and I'm not getting many replies.

Just trying to work out how to set it up and link with the extension etc. I've installed the Parity app on an old phone and I've added the extension to Chrome on my laptop. I'm not sure how I'm meant to connect the two and I also don't understand why I had to create an account on both of them and keep a seed phrase for each one. I watched a video that says that Parity is not a wallet, but if that's the case why did it give me a seed phrase and a public key? I just want to get my coins off the exchange but I can't get my head around the set up. If anyone can give me a step by step or an ELI5 then I'd be grateful. No DMs, they're disabled anyway. Thanks