So you can learn about the rock-paper-scissors formula either by trial and error or in talking to some NPCs. I think the guy just inside each gym will also give you tips.

However it's worth noting that Generation 1 (like Pokemon Red) has a number of unintentional bugs programmed into it. As a result Psychic type Pokemon are extra powerful. If you can get one of those, you'll be in good shape.

Additionally, some of the early game can be difficult to figure out. For example if you picked Charmander as your starter, you might be OK with Viridian Forest, but the first two gyms and related battles will be much more difficult.

Gen 1 is also missing A LOT of quality of life improvements. If you can, I recommend Pokemon Fire Red (or Leaf Green). It's the remake of Gen 1 and it's for the Gameboy Advance.

Printed guides existed for the game, I had one as a kid. But I didn't get it until after I had already played through the game.

You can learn the type advantages by a trial and error. You can learn what types Pokemon are by catching them.

The game tells you when a move is not effective. If that happens, try another move. You'll eventually learn the type matchups.

I learned most of it by trial and error as a kid with fairly shaky English. Most of the type system is fairly logical, and some other internal logic starts making sense after a while - mind you, that logic is still relatively weird in gen1 particularly. As a quick tip, get yourself an Abra or other Psychic type, they are broken as fuck in Red/Blue and you will be meeting a lot of important trainers who are susceptible to Psychic damage.

If it's not for you, that's fine. It was "early days", it's unpolished, buggy, and so on - and that's if the other Pokemon games are your thing. Try FireRed/LeafGreen, they're the same game but in a gen3 "engine" that's a little less primitive.

Why are there downvotes? This community needs conversation! Just play what makes you happy OP. You don't have to love it.

Before the internet, people figured it out on their own, because you got like two games a year, and not figuring it out meant six more months of Tetris.

FYI, "Pokemon FireRed" is the same game, but with a ton of usability issues fixed.

Don't forget there was a cartoon on TV at the same time to promote the game that also explained a lot about the mechanics.

And the internet was already a thing at the time. GameFAQs was in it's prime.

When you’re battling a Pokémon, go on bulbapedia and check its weaknesses

You could catch Pokemon with good IVs and then train the correct EVs to make a good team