Advice for a 7-hour marathon CTF? (Transitioning from picoCTF)

Hey guys, im 17 and currently prepping for a big international under-20 security competition. I've done around 150+ medium challenges on picoctf but the format for this one is pretty intense: 7 hours a day for 2 days. Tasks have multiple subtasks (4-8) that all share the same codebase or binary. Als