What is the natural progression and how do I gear up ?

Hello everyone

I am not new to the game but I have not played in a long time and decided to hop on to season .

I am trying to build a warpath VK for the first time and I see people just destroying the campaign in 1 hour and then they are 200 corruption in a couple of hours.

I have spent almost 13 hours so far and haven't yet finished all the time lines on normal .

Am I missing something or a skip I could be doing ?

one last question I know from guides that I need a world splitter and I don't see that build cleaning the harbinger to get it do I need to switch back to judgement until I get that weapon ?

Thank you for your help