Having leveled up four characters to Grandmaster, with a 5th on the way, I have learned many things over the course of that time. There are a few things I wish I had known about, and done differently while leveling those characters.
Since this game seems to be school/student themed, I think it would be nice to have a "school room" available for volunteers to host tutorials on things like spending training points wisely, tips on using treasure cards, how to make treasure cards, battle strategy, etc. You could make announcements over the chat system (that even menu chat players could read) that stated the time, location, and tutorial subject so that all who wanted to attend could go.
I think having basic tutorials like this available would help out many new players. I know I wouldn't mind volunteering for it.