Ancient power is an egg/level-up move. It has no TM, and therefore Pokemon can only learn it by reaching a certain level or by going to a move tutor, assuming the move can be learned by the Pokemon.
Ancient power in not a TM.
There has never been a TM called Ancient Power in any pokemon game. The nearest equivelent is the move Silver Wind (which is TM62 in both 4th and 5th games.) This is a bug type move and has the same effect as Ancient Power.
You dont
Ancient power is not a TM in this. Hidden power however is given by the professor after 100 pokemon caught
you can find zapdos in the power plant.
you find mew at the power plant after 21 bagges
You cannnot find Ancient Power as a TM, but Move Tutors and Pokemon can learn/teach them to for you.
i think if you go into the kanto region you find it in the power plant
Some Pokemon learn AncientPower, but there is no TM for it. There's Hidden Power and Secret Power, though.
You cannot find Zapdos in Pokémon Silver however it can be found near the Power Plant in the Kanto region in Pokémon SoulSilver.
Sadly there is no TM for Ancient Power, some Pokemon learn from birth or levelling, like Tangela, Yanma and Piloswine, when they learn Ancient Power and they evolve into Tangrowth, Mamoswine and Yanmega. So catch a Donphan (female) and a Piloswine (male), put them together and you will have a Phanpy with birth move Ancient Power. Go to Bulbapedia to find out more.
You can't find Mew in Pokemon Silver.