((Teaching your pokémon a TM move is done by inserting the TM disc into your pokédex, selecting the pokémon and then exposing them to the burst of light/information that comes out of the screen. They'll then know the technique as if remembering something they'd forgotten. However, they'll only know the absolute fundamentals and won't actually be any good at the tech.
If you're getting a TM, it should be from the location you can get it from in the games. For example, Wayne found a Double Team TM in the Dreamyard, since that's where you obtain one in Black and White.
There's no limit to how many moves your pokémon can learn as long as they can legitimately learn them. I think Egg Moves might require backstory, but I personally don't have an issue with the pokémon knowing them if the trainer tutors them in how to do it. If you show their parentage to justify their knowing a move, then no training post is required to show the pokémon actually learning
how to use the technique.
Making sure that you spend at least one post getting your pokémon to practise the fundamentals is required though. If you don't do that, even if you learned the move via TM, it's not going to be an effective technique and your opponent can take advantage of that.
Gym Pokémon typically have whatever move is available to them as Gym Leaders have both the time and inclination to teach their pokémon as wide a variety of techniques as possible. Plus this helps us play the Gym Leaders; it makes it easier to battle effectively with pokémon we're not familiar with. Challengers are expected to have had plenty of time to train with and get used to their pokémon.
You probably shouldn't try to teach your pokémon every move it can know in a single day though. Because I don't think that'd be allowed
razz ))
Watchog decided not to abandon all the years of training he had to not be distracted by big sparkly things and keep his attention on Iron Hide. He'd blast the ground where Iron Hide should've surfaced to find that the pokémon had chosen to remain underground somehow.
Spike would disappear and then force Lenora's hand.
"Tactic 84."
Herdier used Surf on the hole that had been created by Focus Blast, which sure enough revealed Iron Hide's tunnels. If the challengers were meeting up to discuss strategy then their tunnels would also be connected.
So by using Surf, Herdier would quickly and violently flood the challengers' tunnels. So unless they wanted to drown, the two pokémon would have to resurface. And thanks to Surf, they wouldn't be able to try and get close to the gym pokémon and attack them.
When Spike and Iron Hide decided to not drown and climb out of Lenora's arena, Watchog would immediately go to shoot the first one to leave with Focus Blast.
((I caused a fire while writing this as it distracted me from the 3am snack I was making. Damn you, TK. Damn you.))
***
Meanwhile, the skies of Nacrene were privy to an extraordinary sight. Antiq soared the skies, flapping her magnificent but scaly wings to generate surge after surge of forward momentum. Y'know. Fly.
Anyway, Antiq was an Aerodactyl and a big one at that. Once over Nacrene, her riders leapt off. Speeding through the air without a parachute and probably terrifying anyone who watched. But then they'd spin and hit the ground.
His knees bent as he hit the floor with both feet, holding her in his arms to land for the two of them. As the pair struck Nacrene's streets, the tarmac would crack, creating rings of broken ground and shattered floor. It seemed to take a moment for reality to accept what had just happened, but neither of them were injured in the slightest. The tremors stopped and they straightened up.
He let her stand on her own, cracking his neck and waving off Antiq, who turned in the air and broke the sound barrier with an almighty flap of her wings.
"Finally," Zack said, "We're here. That took forever."
"At least we arrived," said Elizabeth, stretching, "I forgot how cold flying can be."
"It wasn't that cold," Zack looked away, placing his hands in his pockets. Elizabeth let off a wry smile and shook her head. It certainly wasn't...
She put her hands on her hips and piped up with, "So let's hurry up and register for this tournament thing. Then we can find Wayne and, I dunno, get some sleep?" Elizabeth tipped her head forward in exaggerated defeat, "I am
so tired."
Zack took a few steps about the city street, looking around. Then he turned back to Elizabeth and nodded with a barely-noticeable smile, "This'll be a big shock."
((This is they -
BAM - only without the snow and wearing clothes appropriate for spring
ninja ))