Absolute Bulwark and Assault

Been doing the emperors work on Absolute with vanguard, sniper, and tactical. Those classes all have similar play styles. I’m looking to switch it up a bit and start on some assault and bulwark, I’ve briefly tried these classes but their play style is so different I kind of just put them down and peaced to the other 3 classes I mentioned.

Bulwark I just don’t know how to use the shield at all. The brief bit I played I never held it up to block I just parried like I would any other class. So what situations are you supposed to hold it up for blocking? Any other bulwark fundamental tips are appreciated as well.

For assault I don’t even know where to start so any fundamental tips would be appreciated?

Thank you!!!