If you mean how to get the other starters other than the one you chose, the only ways are:
1. Trade (link or GTS)
2. Hack with PokeSav, or Action Replay
If you mean how to use ledgendaries as starters,
1. Hack with Action Replay or PokeSav
you cant get a diamond on Pokemon pearl but you can get a pearl on diammond ...and pearl.
Pokemon no.147 in the Pokemon Pearl National Pokedex is Dratini.
how to get shining Pokemon on pearl vershow can you get shining Pokemon in pearl version
You can not get Balbasaur in Pokemon pearl
What is the pokemon pearl ID?
Yes, you can get it on Pokemon Pearl.
There is no mime jr. on Pokemon pearl. On diamond there is mime jr. on Pokemon pearl there is bonsly
Hayley is a character in My Pokemon Ranch, not Pokemon Pearl.
Trade with Pokemon Pearl or Pokemon Platinum
The Pokemon 47th in the pokedex on Pearl, is Mothim
No. Just like in Pokemon Pearl with the Pal Park you can only trade from Pokemon pearl to black, not back
Pokemon Diamond Pearl and Platinum are games in the Pokemon series. There is no secret store in Pokemon Pearl version.