As a general guide for scenario events read the player pack and forum threads to get an idea of the game theme & missions if shown in the pack
Decide what you want to get out of the event. You might want to shoot at lots of people, attack or hold objectives, or sneak around the whole field and gather point winning props etc
Make yourself known to the sides leader or tack on with a team, and offer your services based on what you want out of the day
Events don't necessarily win or lose on eliminations, but they certainly help to deny the opposition the manpower to go for their objectives
Keep in touch with whatever command chain there is as objectives are often time critical, plus additional side objectives will be required from the commander. What was a priority at 9am won't be at 12. Whenever you respawn check in for the latest status
Find out if there is a tradition on a long standing event such as a certain side dominating the morning then all going for lunch at once and struggling to catch up all afternoon
At many events you get a lot more out of it by camping. But if you are a light sleeper then a hotel may be a better bet for a good nights sleep.
However there's always somewhere quiet to camp if there is an all night party going on in half the camp. In most events the all nighters will be considerate to the sleepers
If you camp you have to be dedicated to your sleeping to be late. If you stay off site then you need to be up and away promptly to guarantee a good start