you want deaths dance for sustain so rush that
then finish your jungle item red smite for melee champs blue for anything else but this is up to you
then you build all 3 leathality items
boots of your choice depending on what you need
last item can vary you can get BoRK for life-steal and attack speed GA for survivability its up to you but i would recommend GA for the second chance

start chickens(raptors)>red>wolves>blue
Gank top (if you need help smite scuttle)
gromp/invade if possible
back then do a full clear
Gank whenever possible or needed and don't forget objectives such as drake rift(especially in lower elo's people don't know how to deal with it

your job once you have a few items is tho go in take out the adc and mid laner but dont worry if you cant do both you're damage should be very high (as long as you don't get behind) and try to get out
the mixture of damage will allow the deaths dance to give you a lot of sustain that is why its in the build

you will be fine as long as you don't get behind and remember as a jungler you are there to help your team help them get kills and dont take unless necessary prioritize the lanes with ranged champs as well to help you get shadow assassin faster
Gl HF summoner