Quantum Resistance

To my understanding if you send BTC/BCH to a fresh address and don’t spend from it then your public key is never exposed therefore no worries of quantum computers extracting your private key.

2 questions.

1) if you’ve been spending from a wallet would you need to set up a new private key, or can you just send all to a fresh address within that private key and then be fine? Basically if you’ve ever moved funds from a private key is that going to be compromised in the future and therefore need to set up an entirely new wallet? Or is a new address within the private key fine?

2) what is BTC and BCH developing for quantum resistance.