>>49867392
Prior planning is essential if you want to do anything more than just soak up the atmosphere. Most importantly, figure out what groups/areas you want to see and have their location recorded somewhere (what hall, hall number, column, and stall number).
I use the online catalogue to look up and mark circles that I can print out for quick reference on the day, but you could also look up the twitter of some artists you know and see if any of them are participating (if so they'll have the details as part of their handle) and paste 'em onto your phone.
Tomorrow is mostly original male-orientated doujinshi/vtubers/touhou, so you should be fine just looking around 東4-7 if that'd interest you, or visiting the corporate booths at 南3-4 for general merch.