River Shen starts on top lane side in the river bush. You may roam top or mid at the start of the game use all your summoners and ****. NOW THE MOST IMPORTANT PART at 3:15 ignore evertyhing and go for scuttle now there are 3 things that can happen (a) YOU GETTING RIVER SHEN SCUTTLE CRAB TECHNOLOGY, b) your jungler stealing scutlle, c) enemy jungler stealing scuttle):
now what to do:
a) Go on you are on your way to become FULL FLEDGED RIVER SHEN GAYMER
b) Go run down mid for each scuttle that he stole out of your sight
c) Ping to your top mid, jungler to help you and try to Q E enemy jungler.

NOW how to get xp as river shen before scuttle initial spawn:
stay on mid in bush and leech xp or after helping stay on top mid to leech but dont last hit minions becaue RIVER SHEN TECHNOLOGY LETS YOU ONLY LOVE SCUTTLE CRABS AND KILLING A MINION MIGHT RUIN YOUR WHOLE GAME!!!

HOW to use chat as river shen:
Lobby - Say 1 "River Shen" WARNING: its case sensitive
Start of the game - 1 "River Shen" but not on all chat never do it WARNING: its case sensitive

Game - After helping do 1 "River Shen"WARNING: its case sensitive after getting something stolen spam "River Shen" for few seconds WARNING: its case sensitive

I think thats all there is also nice guide on youtube i wil be sending it here so you can learn RIVER SHEN TECHNOLOGY!
https://www.youtube.com/watch?v=XyqUpLRiF6Q&t=204s