Three of those you can get by trading Pokemon in game for them
One from pidove in Ametrine city
The others pidgeot & farfetched in 7th st though you need to be carrying a helix fossil and no done fossil in your bag
Archen and Tortuga are in the circus as puzzles
Some are inevitable, sometime you have split desicions that effect diffetent people in positive or negitive ways, it doesn't matter too much just have fun
Budew hasn't it needs to be a clear day and you have to have rose insence from the doxy or from lapis flower shop
Budew requires your rose to breed holding the rose insence
Or after you renovate the slums it becomes available to catch in wild in the park and by the Soltice during morning/day I believe it was
So ignore the clear day part it's rainy all the way https://www.youtube.com/watch?v=RT1fnlShh1g
It was changed from Charmander to Litten so if you already did the quest your locked out of it currently
So Litten and Mudkip for you then? Also do you care about IV?
You can still get Squirtle without Taurus
That happens if you got oshawott from the lighthouse I can give you all three or I can give u a link to find squirtle on your own?