Age 24
Male
England
Seen September 16th, 2020
Posted September 15th, 2020
Hi there Nismo :)
I guess if you only have a 3ds the order you'll have to play the games will be Yellow>Diamond/Pearl>Platinum(not compulsory) >SoulSilver/HeartGold>Black/White>Black 2/White 2>X/Y>Omega Ruby/Alpha Sapphire
Although, anything that comes after Yellow and before X or Y on that list will have to be purchased in physical form as digital copies are not available for the DS Pokemon games.
Just head down to your local game store and you should be able to buy some in the pre-owned games section, though they can be really expensive...especially HeartGold/SoulSilver...
Concerning transferring your Pokemon, you'll need two different systems to do that with most of the games but you can transfer Pokemon from Black/White and Black 2/White 2 to X, Y, Omega Ruby and Alpha Sapphire using the Poke transporter. Also Pokemon from your Yellow Version can be transported to the upcoming games Sun and Moon with the use of Pokemon Bank.