After putting in a report to HQ where they took credit for taking down Team Galactic, Giovanni decided to send the trio over to Unova to try and spread Team Rocket's influence and start trying to take over the world. It's also revealed Giovanni wants to know about a new rising syndicate in Unova so he wants agents there (he doesn't tell the trio this, though). It just so happened that Ash was also heading to Unova however being he isn't there main target the Team Rocket trio only attack him when they either run into him or are waiting for their next mission objective.

Ah, I see. So it started with them reporting that they defeated Galactic. I guess they could've been successful those countless number of times had it not been for Ash. Thank you.

There are a few places, Bulbapedia has them listed HERE. Oh, and if you're looking for a King's Rock there are only three ways to get those: 1. From the Treasure Hunter on Route 13,2. a 1% chance of it being randomly gotten from the Ability Pickup if the Pokemon is between levels 11-30 (Lillipup can have the Pickup Ability if you're wondering and it took me only a few days to get the two King's Rock I needed), and 3. Wild Poliwhirls and Slowbros might be holding them.

As for the Incenses just go to theDriftveil Market and a former Team Plasma grunt (who's still wearing her armor for some reason) will sell them to you.

Depending. There's a couple worth while pokemon by then.

And, you need both black and white to collect all of the Unova/Isshu Pokemon.

What Pokemon you choose to train is up to you, however if you need a Pokemon to battle the 3rd and 4th Gym with then for the 3rd Gym (which is Nacrene City/Lenora/Normal-type) you can find Fighting-types in Pinwheel Forest (Timburr is there and depending on what version there is Throh (White) and Sawk (Black), though there is a 5% chance you can find the other one in shaking grass). As for the 4th Gym (Castelia City/Burgh/Bug-type) if you don't already have a Fire-, Flying-, or Rock-type (all three types wereavailable in an earlier place in the game) and you don't want to backtrack then on Route 4 you can find a Darumakaand in the Desert Resort you can find a Dwebble (and also Darumaka).

As for catching all the Unova Pokemon, well of course it's possible however you'll need to trade with the other version and get all the event Pokemon. Click HERE for versionexclusivesand HERE for event Pokemon and scroll down to "Black & White/Generation V".

Which one?