Can I....?

Let's say i want to have a set (10 or so triggers) be not enable at the first, but after an elapsed time.

Can I make enable all those triggers after an elapsed time? and at the same time disable those that were used at the start?

Yes. Just uncheck the box marked 'Initially On' (or something like that) on all of the triggers you want to be off initially. Then set up a trigger like this:
Event
-Elapsed time is X.XX in Game time
Conditions
-None
Actions
-Trigger - Turn On <Name of Trigger>

Add this action for each trigger you want to turn on and the reverse for each trigger you want to turn off.