In MR1, some techs are available at training from the very start of the game, others don't seem so easy. It's pretty simple here, you just need to get the stat that it's based on (look at the Training place where you get the attack, see what stat it raises, and raise that attribute) up another level, that is above 300 or 600. If that doesn't work, there are a few attacks which require the attribute (Power or Int.) which the attack affects to be over 600.