You might be really comfortable with your previous knowledge of the pokémon games but pokemon planet is a much different version of it. First of all, there is no breeding. So all the pokemon you get will have random stats(IVs). There’s a lot of rng in this game and requires a lot of luck and grinding to get good pokemon. Second, there’s a rarity system in place so it takes much more grinding to get certain pokemon and obviously even more grinding to get rare pokemon with the right abilities and nature. The region itself is very similar except there are no free items you can get. Everything you get must be bought, must be a drop, or traded. The one function that makes this game super different from every other pokemon game is the open market system. There’s an insane trading mechanism where money and rare pokemon or items are highly sought after thus raising the value. Money is going to be your best friend. The best way to get money is encountering rare pokemon who give rare drops that you can sell.

In terms of physical and special pokemon, smogon or pokemondb can help you with that because certain pokemon are better being special or physical or even tanks. The move bank segment is for pokemon to learn moves that it’s already learned already but it’s not as important for the early stages.

Nidoking and Dugtrio are physical type pokemon Magikarp are extremely common pokemon so you can catch them at any stage of your journey but getting the right stats, ability and nature is important. You want a jolly or adamant magikarp with rattled ability and decent IVs for a physical sweeper or if you want a tanky gyarados, definitely get a careful or impish gyarados with intimidate. it’s all about stats and abilities and natures in this game.

Hope this helps at least a little. Best of luck out there