How to get Bulbasaur and Squirtle
Pokemon Red and Blue introduces players to the world of Pokemon, starting with allowing players to choose between Bulbasaur, Charmander, or Squirtle as a starter. Out of the final forms, Charizard is easily the most popular of the bunch, so there was no way to cut him. Bulbasaur and Squirtle weren't so lucky as they did later on.
Pokemon Sword and Shield's first expansion, Isle of Armor, changes things by introducing several Pokemon that were cut from the original game. Even though Bulbasaur and Squirtle have been added as Max Raid Pokémon before, it was only for a week and they are gone unless you traded them.
Now you have the option to get these cut starters in Pokemon Sword and Shield directly as long as you have the expansion pass. To get Bulbasaur and Squirtle, start your game and head to the Isle of Armor by train. Once there, talk to Klara and head to the Dojo. Here you will meet Dojo Master Mustard and ask to participate in three trials, the first of which is to find his three Fast Slowpoke.
After you take down all three Fast Slowpoke and collect Klara's Dojo outfit, you must return to the Dojo itself. At this point, you will be rewarded for your hard work at the bottom by offering you a Bulbasaur or a Squirtle to keep. You can't have both, so you have to make the choice here for which one you want.
Whichever one you choose, your new Pokémon will only be level 5. However, there are some very high level Pokémon here, so you shouldn't have much trouble breeding them through the use of the game sharing experience.