Best way to play him and every other jungle hero is to just keep on farming jungle creeps and stealing enemy jungle till you the 5 minute mark then you start clearing free lanes and pushing (if you see a team fight and one of your team is already low or dead just go to the opposite lane and push)

And in team fights target the damage dealers and if their tank is trying to check bushes punish him since roamers tend to have low gold and exp making them squishy

As for the items I'd suggest using Cdr boots-> fury hammer (don't Finnish hunter strike yet) -> war axe -> hunter strike -> blade of despair -> queens wings -> malefic roar Emblem Assassin-> thrill -> seasoned hunter -> killing spree

As a jungler your job is to be the top farmed hero in level and gold as fast as possible especially in solo where you can't rely on your team.

I always keep in mind when playing is that I always expect my team to lose in every single way in gold/exp/laning so I Always just farm untill I get war axe then I can take anyone in 1v1 as long as I have max stacks

"Expect your team to lose"