Very cool!!
Early on, expect to die a lot... the only way to get around it is to spend a couple of days doing vanilla style MC stuff... which isn't horribad, but it's not the only way... just the easiest if you've never done Hexxit before.
And even then, when you get lucky and an Infernal Creeper spawns outside your shit with 80 hp and like 9 debuff auras, you're just boned.
The best plan of action, in my opinion, is:
Trees -> Table -> Wood Pick -> Stone Pick/Shovel/Axe/Sword -> Stack of lumber -> Stone Armor (if that mod is still in) -> Find the nearest doable structure and just fucking banzai charge it. Make little safe areas as you clear it, bed down there to bind, clear a couple floors, new safe area/bed... once you're done, you're probably decked the fuck out and you have like 9 chests of shit you'll never come back for hahahaha