i like to play riven jungle because it require far less skill to be effective on her. Riven top lane requires you to know how to play the matchup well to even have the slightest chance of snowballing, but in the jungle the only matchup you is the jungle camps and they are easy to outplay (hehe XD) and ganking iwth 40% CDR on riven is easy because people poo themselves when they see her run out the bush its either a kill or a flash 70%-80% of the time

The main Aim of riven jungle is to power farm the early game till you get youmoos and then you can start ganking with your lvl 6 and youmoos burst, Just keep an eye out for easy kills in lanes to help you get your snowball rolling

Once you have your core Of Youmoos and black cleaver you can gank any lane without a problem because you will be soo ahead from all the farming you been doing this is where you need to be fairly skilled in riven to start carrying you will sacrifice the early games of your laners for the INSANE carry potential of the mid to late game riven. Pro Tip tell your team to never push their lane and only last hit (Freeze their lanes) to avoid the chances of the enemy jungler getting a lead off ganks

Honestly i used to be the worst riven player anyone could ever know but if you really want to get good at riven you need to spend a lot of time watching videos on riven and praticing combos to the point where it is just muscle memory. kinda like playing a fighting game, you remember combos like its your own phone number this is how you need to play riven. Just keep playing Riven in normals.

Pros:
Easy to learn riven
No hard Match ups
Easy to get a gold lead
Good CC and Mobility for ganks
Insane Carry potential

Cons:
Can be invaded early but just back off and wait for your laners to help
First clear is a bit rough at first but you get better at it