Quantum computing it self is complicated beyond  what you might be thinking(maybe) but you can grasp the  required basic knowledge of what it's all about just like most people(including me) . 

 BIP360  is just a proposed standard against upcoming quantum computers era, the current stage of quantum computing is still prone to errors like decoherence, still in development phase but expect to be  somehow  upto some certain  task in a decade like breaking ECDSA/Schnorr sig because of Shor's algorithm, you can read that here https://research.ibm.com/projects/quantum-safe-cryptography .. as mentioned (decade is just the speculative time could be lesser or beyond but even at the moment  there's a significant progress already)..

 You can read: https://www.ibm.com/think/topics/quantum-computing.. covers a lot about quantum bits (qubits) and other important basic parts.. 

Also, just as I've  said earlier, Bip360 is just a proposal for now so there's  not too much on it yet until it gets accepted IMHV until then you can still see what it's  all about in the link anyways.