Vincent, Jimmy and Marina from Pokemon?

No there is no episodes where they get there starter pokemon. Its because the "The Legend of Thunder" was originally a made for TV movie back in japan and thus the movie explained their back stories a bit at times. Vincent however does appear in Season 5 (master quest) in the Jhoto league cup fighting Ash in the Episode "Tie One On!". However Vincent is referred to as "Jackson" and he talks about Jimmy and Marina as if there names were "Dani" and "Yoshi" mainly because 4kids the original dubbers of the show had an inconsistent dub and apparently forgot what they originally called them (Eusine who was called Eugine in The Legend of Thunder also had this problem). In one episode in the Diamond and Pearl part of the anime Marina makes a few minor cameos on merchandise and such (according to bulbapedia about four or so).