Everyone has to start their Pokemon journey somewhere, and where's the harm in getting a little help to do it?
The Pokemon on this list were picked based on easiness to find/catch them, simplicity of use, immediate usefulness and overall efficiency. It is to be noted that there may be better options for certain sections of the game.
However, these Pokemon should help beginners on their way to conquering the Kanto region for the very first time.
Note: This article is subjective and reflects the opinion of the writer.
Best Pokemon that beginners should use in Red and Blue
#5 - Diglett/Dugtrio
Diglett or Dugtrio is the best Pokemon to use to beat Lt. Surge in Vermillion City on a beginner's first playthrough.
Diglett (or Dugtrio, should the player get lucky enough to catch one of the wild ones) is the ultimate bane to a gym that can otherwise prove troublesome.
Of course, that's not the only reason for a new player to pick up a Diglett. It also comes in handy once it has evolved into Dugtrio, being useful in the Fuchsia and Cinnabar gyms and eventually learning the powerful move Earthquake.
In addition, if the player starts with Bulbasaur, Diglett/Dugtrio will be able to take care of the rival's Charmander/Charmeleon until the player picks up something that can deal with the Flying-type Charizard.
#4 - Squirtle
While everyone has their own preferences as to which Generation I starter is the best, Squirtle is likely the easiest to pick for a beginner.
Squirtle is effective at dealing with the first gym and resists the most damaging moves from the second gym. This gives beginners a chance to learn how to play around type effectiveness without getting hard-stuck by their starter being useless in both gyms. Later in the game, Blastoise can deal with gyms seven and eight while also learning one of the two most valuable HMs, Surf.
If the player picks Squirtle, the rival will picks Bulbasaur, which is the easiest of the three starters to deal with, thanks to it being Grass and Poison-type.
#3 - Jolteon
Eevee is very easily obtained in Generation 1, with a new player being able to nab it from the top of the Celadon Mansion for free. It can also easily evolve, with the player only needing to pick up an evolution stone from the nearby Celadon Department Store in order to evolve it.
Out of the three Eevee evolutions in Red and Blue, Jolteon is the most usable. Its stats are good and are applicable to its learnable moves. The fact that it is a good Pokemon to use against two of the three potential rival starters makes Jolteon an excellent pick.
#2 - Lapras
Lapras is another easily obtainable Pokemon. The player can naturally obtain it while progressing through the game.
Lapras has exceptional stats, making it usable from the very start. It also works well against the seventh and eighth gyms and against two out of three of the rival's starters.
If the player hasn't caught a Pokemon that can learn Surf yet and they didn't start with Squirtle, then Lapras can fill that role.
#1 - Snorlax
Snorlax is one of the best Pokemon in Generation I and is not rare in the slightest. In fact, the story requires the player to awaken at least one of two slumbering giants, making an encounter with the tubby Pokemon unavoidable no matter how new a player may be.
While not the simplest Pokemon to catch, it's still within possibility for a beginner to catch a Snorlax with limited difficulty. And if they do, they'll have a beast of a tank with devastating offensive capabilities and almost no weaknesses. This is easily one of the best Pokemon for a beginner to add to their team.