Restarted, few q's

I restarted yesterday and bought the trilogy and Eye of the North. My current budget is 300k (just in case this affects any of the answers). I am playing a warrior through the Nightfall campaign and kind of struggling. What are some tips or builds that I can use to get through the Nightfall missions so I can unlock heroes. Thanks to any who help.

Please use search and have a look around profession guides.