[Quick Question(s)] Jungle Decision Making

Just had a quick question(s), since I'm kind of a new jungler.

So I was playing Wukong on purple side vs. a Rammus (Had to pull this match history from Summoner Caoil's match history, since for some reason this game isn't listed on mine. She played Thresh, and did really well I might add). I started blue, went wolves, and my top lane pinged that they warded my red, so I (like I usually do) face checked my red side bush and sure enough, there was a Rammus sitting there. Why a Rammus would go for a lvl 2 invade on a Wukong, I have no idea (maybe there's a legitimate reason, but I don't know what that reason would be), but we danced around for a bit trading a little damage and I decided, since he was just sticking around, to ward my red and go do my wraiths. My thinking was: If he decides to stick around (which he did for a while), he's just wasting time, meanwhile I'm just farming wraiths so I don't lose any time, and if he goes for my red I can easily make it back to contest. Was this a good decision to make? He left soon after and I just went back and did my Red.

Even with this time Rammus wasted, I was still behind like half a level (he was lvl 4 when I was ~3.75), I don't know why but I always end up a little behind as Wukong, maybe I'm not picking good jungle paths (I try not to walk past dead camps) or maybe I'm not soaking lane experience (I didn't see any easy gank opportunities after I hit lvl 3-4, we had a Ryze mid pushing in a Xerath, Olaf vs a Nidalee top who is really hard to gank, and my bot lane Lucian/Thresh was pushing vs Fidd/Varus, so I farmed another camp or two and backed, idk). Also I never ganked for Olaf; I figured I wouldn't be able to do much vs. Nidalee, plus Olaf was up ~20+ CS on her most of the game. Should I have snowballed that lead harder, or was it okay to gank bot/mid/work for dragons more? Thanks!