Since Pokémon Light Platinum is a ROM hack of Pokémon Ruby, you should have no problems using your old Pokémon Ruby cheat codes for it. [1] X Research source
This is where you’ll add the codes that will allow you to play around with the game’s RNG, or Random Number Generator.
When this code is enabled, you will get 99 pieces/units of whatever item is in the first slot of your PC’s Item Storage. Additionally, the item will always stay on the first slot even if you’ve withdrew all of it to you bag. Essentially, you’ll have an infinite number of whatever item is on the first slot.
Since this is a Codebreaker code, it’s best that you add this to your cheat list separately from the Infinite Item code. It is not advisable to use this code by itself since it might cause your game to crash.
Due to its high damage output, Charmander’s Scratch should make short work of any Wild Pokémon you come across at this point. If you do come across a Pokémon with a high level, you can always Run Away.