I have created a wallet using Electrum. Electrum creates 20 receiving addresses. My question is can these be linked or traced back to each other?
I want to understand if I have create another wallet if I want more receiving addresses apart from 20.
I'm not 100% sure, but as far as I know this is not (easily?) possible. The addresses used for sending/receiving payments are created using your initial private key (THe 20 word long seed) in a deterministic way. When creating a new wallet with this pivate key, the same addresses are generated.
It is not possible to guess your private key having one or more of your addresses. I think it's also not possible to guess which private key has generated the addresses.
You should use an address only for one transaction.