Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
Since I've gotten this endorsement from the wonderful - understander, I think it would be cool to post my video. A moveset guide for "every" Pokemon in Doubles, with handy time stamps in the description to thumb through to your favourites.
If I missed a Pokemon you care about let me know. If there are enough of those I guess I'll make a follow up video!
Friendly reminder to players in the teambuilder - certain Legendary Pokemon should always be Shiny or not Shiny so as to not leak information.
Genesect should always be Shiny - it's the only way it can have Shift Gear.
Heatran should always be male and not Shiny - it's the only way it can have Eruption.
Zeraora should always not be Shiny - Shiny Zerarora was only released in Gen 8, so it can't have Gen 7-exclusive moves like Knock Off.
Even if you're using say, Scarf Genesect without Shift Gear, it's still optimal to use Shiny Genesect so you don't give up that information on a possible set you could be running!