You don't need to restart because of that, you get all of the starters from different NPC's. You get Bulbasaur in Cerulean, Charmander on Route 24, and Squirtle in Vermilion. You just have to catch a certain number of Pokemon, key word, catch. It doesn't matter how many Pokemon you have in your box, if you've caught 41+ Pokemon, you can get Bulbasaur, if you've caught 51+, you can get Charmander, and if you've got 61+, you can get Squirtle
Sorry for double post, but if anyone who has Let's Go Pikachu is willing, would you be able to trade an Oddish for a Bellsprout, and maybe some other version exclusives?