So that's what most Rengar starters/players have the most problem ganking before level 6

Well actually its pretty simple for example your botlane is pushing and you have oracle lens already so you can just go to the bush check for wards and tell them to bait or just wait if you dont have nothing to do since they are pushing wave should reset soon, when the wave resets they might start trading and thats where u shine, same thing with the toplane. Avoid minions seeing you. When ganking botlane try to avoid bush that is next to drake, because most of the time its warded and they will spot you. I circled the bush in this imageIf you interested in ganking midlane, try to look at the map when you are near midlane and if you see enemey midlaner pushing towards your midlaner, you just go into the bush and check with oracle lens if there is no wards that means when midlaners push they go get vision or recall. So you can also chill a bit in the bush

So that's what most Rengar starters/players have the most problem ganking before level 6

Well actually its pretty simple for example your botlane is pushing and you have oracle lens already so you can just go to the bush check for wards and tell them to bait or just wait if you dont have nothing to do since they are pushing wave should reset soon, when the wave resets they might start trading and thats where u shine, same thing with the toplane. Avoid minions seeing you. When ganking botlane try to avoid bush that is next to drake, because most of the time its warded and they will spot you.
If you interested in ganking midlane, try to look at the map when you are near midlane and if you see enemey midlaner pushing towards your midlaner, you just go into the bush and check with oracle lens if there is no wards that means when midlaners push they go get vision or recall. So you can also chill a bit in the bush

Objectives are one of the powerful things in the game for example drakes, baron, herald etc
As a Rengar I love to do drakes when I recall and get first item(tiamat) and its very good for your team also getting objectives early game. Most of Rengar players just ignore herald etc herald is stronget objective in mid game, because of the damage he can deal to turrets, I recommend to take herald at 11-12min, because turret plating fall off at 14min and herald spawns at 10 minutes platings are good. So when you took herald for example you can go and gank some lane( I also recommend ganking a solo lane because of the gold you can get) For example you gank mid you kill enemey midlaner you release herald and get platings. Try to take as much objectives you can, because objectives can win the game.

Your goal in mid game is to snowball as hard as you can by snowball I mean, kill enemey in jungle or in lane and try to put them behind and yourself ahead, you can also splitpush and get solo lane experience if you fell behind, because you are useless if you fell behind as a Rengar so try to come back into the game

Late game is similar to a mid game, but in late game you have to be more careful, because death times are way bigger and champions get stronger. So your goal in late game is just to oneshot as many people you can ! If they have hard cc comp or like tanks, you are useless so u go splitpush because Rengar also does tons of damage to turrets and is one of the best splitpushers in the game.

PROS
Fun to play
Strong
Really good to snowball/splitpush

CONS
Useless if you fall behind

Rengar combo is pretty simple once you get it its very effective, you can practice it in practice tool on even in normals so the combos would be

ONESHOT Combo would be Savagery Bola Strike Battle Roar over powered Savagery