Welcome to the Waaagh! and welcome to Dakka.
Firstly, I'd like to direct you towards the Ork tactica thread, the link to which I'll put in spoilers below.
Secondly, as far as the direction you take your army in it wholly depends on what style of army you want to play. Orks do well when they lean into one style of play and target saturation; lots of infantry, or lots of vehicles/hard to kill targets, typically not a mixture of both.
What I will say about the models you already have is that nobs as a units are currently underwhelming for their points. If you've not already built them, I would build them in the various melee weapon options so you can adjust the boss nobs for your boys mobs between games without having to magnetise or rip the arms off your models.