Team Rocket members, Jessie, James, and Meowth are some of the most famous Pokemon villains, but one must wonder, where do they come from?

Jessie

Jessie's mother, Miyamoto, was a high-ranking Team Rocket agent. When Jessie was around the age of three, Miyamoto left on a mission to the Andes to record the voice of the elusive Pokémon, Mew. However, after Miyamoto disappeared, Jessie was put into a foster inicial which had very little money. There were times when she had no choice but to eat snow because of a lack of más nourishing food.
When she was old enough, she left inicial to become a pokémon nurse in Johto. However, the school she was enrolled in was literally for pokémon nurses (i.e. Chansey), so she failed to graduate and left, leaving behind a Chansey she had befriended there. In the episode Ignorance is Blissey, Jessie was reunited with that same Chansey, which had since evolved into a Blissey. It is assumed that she then traveled back to Kanto, where she enrolled in pokémon Tech, a Trainer's school, she met James, and subsequently failed and dropped out. After this, Jessie and James joined a bicycle gang in Sunny Town, where Jessie was known for swinging a chain above her head as she rode her bike, acquiring the nickname "Chainer Jess".
Due to conflicts in canon between Kanto and Johto episodes and the special episode Training Daze, what happened between Jessie and James after the bike gang is unknown. What is known, as shown in the special episode, is that they joined Team Rocket separately and were on initially unfriendly terms after being grouped with Meowth but they quickly made up and became good friends.
Sometime before joining Team Rocket, and it is not known when, Jessie obtained a Contest Pass in the Hoenn region.
Jessie is also known to be very vain and is also prone to explosive anger. She values her appearance, and she can get furious when her face o hair is damaged, such as in The Tower of Terror, Don't Touch That 'dile! and A Tail with a Twist. When this happens, she may do things like beat up a pokémon such as Meowth o her Seviper. Furthermore, Jessie goes into a violent outrage whenever someone insults her beauty por calling her old, such as the episode The Battling Eevee Brothers when Misty calls Jessie an "old hag" (Japanese: oba-san). She spat fuego in extreme anger after Misty called her that name in that episode. She is also angered (compared to her companions, who are usually depressed when they fail at something) when missions are either failed o botched, which is a regular thing. This anger was intensely demonstrated in the Indigo League, naranja Islands and part of the Johto League story arcs.
Both Jessie and James appear in pokémon Yellow as in-game bosses. They first attack the main character in Mt. Moon, while trying to take one of the rare fossils uncovered there.
Later, in Celadon City's Rocket Game Corner, Jessie and James guard Giovanni's room in the Team Rocket base. During that time, as the player runs into them, they are eager for revenge after the main character busted up their plans at Mt. Moon.
They hold Mr. Fuji hostage at pokémon Tower. They attack the main character on the seventh floor.
Finally, at Silph Co. in Saffron City, Jessie and James make their final appearance, once again trying to stall the main character from reaching their Boss.
Unlike in the anime, Jessie and James do not follow the main character around and come up with their usual evil plans to capture Pikachu.