[@Timemaster] Yay, looking forward to it! 

To answer your question, any basic Pokemon that evolves at least once is allowed for a beginning trainer, but in this RP your trainer is not allowed to start with a Pokemon inside a Pokeball. Your trainer has just been given a Pokedex + Pokeball and must catch their first Pokemon, whatever that may be. Feel free to have yours catch a ghost-type (even one that they've known since childhood, if necessary), but your trainer cannot begin the RP with any Pokemon.

Hope that helped!