How should I study for long OTB tournaments?
Also, USE YOUR TIME. There is no point in being in a loosing position with a ton of time when you could have used that time to be in a better position. I have lost a significant amount of games myself because I didn’t use my time to the fullest.
@1
"The time control is 1 hour and 30 minutes plus 30 seconds per move"
++ Then do not play any chess game with a different time control.
"it will last for ten days" ++ Then start outdoor physical exercise to boost your stamina
"how to study for it" ++ Do not study.
"lots of puzzles" ++ No.
"warm up games" ++ Yes, but only 90|30, e.g. against a strong engine
"read lots of chess books?" ++ No.
"what should my diet be?" ++ Read this