You can't massage Ochako if you train with her that day, you need to go directly to the chairs.
In case you didn't know, keep to "rock, papper, scissors" mechanic in mind when fighting enemies to use less quirks and you can convine quirks to make a more powerful one.
Also, you can use a "Double H Potion" (you're given one by Mei and find one by exploring the cave's lab) to recharge your quirk uses for the day (recommend you save it for the boss though.) and eat chocolate (bought at the convenience store) to restore health.