Use the pokeflute.
Yawn is not taught by a move tutor it can be learned by some Pokemon such as Snorlax also Slakoth and Slaking.
To move the snorlax, you need a poke flute. You get the poke flute from the old man in Pokemon Tower his house is in the same town as the Pokemon Tower
use the move Flash (TM70)
pokeflute
use the Pokemon flute
Snorlax
i think iy is perfect for league it has gigaimpact and it can so many tms i won league and i has a lv 100 snorlax male and it has gigaimpact a gigaimpact is a move which can learn in lv 49
if you meen in Cerulian city you need nationalpokedex, to get that yo need to take the Pokemon league and get 60 Pokemon
Play the flute to it.
The only way Alakazam can learn Fire Punch is through a Move Tutor on Pokemon Emerald Version.
Use the pokeflute.