First of all, Polkadot is not an Ethereum Killer, in the same way as Ethereum is not a Bitcoin Killer.

To know more about Polkadot, check this article on it's 5 best qualities:
https://www.holdpolkadot.com/post/5-reasons-why-polkadot-is-80-of-my-portfolio

And about Wallets and Staking on Polkadot check:
https://www.holdpolkadot.com/post/5-best-places-to-stake-polkadot